Borax, an important, refined boron product, is obtained by processing tincal ore through dissolution, separation from clay, crystallization, dewatering, and drying processes in factories. Precipitation of suspended clays with flocculant is a crucial stage in the process. In this study, suitable flocculant properties and appropriate operating conditions were determined in a laboratory setting for the refined borax production process. The studies were conducted using samples taken directly from the process and under the process conditions (95 °C, pH = 9.5). Flocculants with different properties (anionic, cationic, nonionic), obtained from a commercial firm, were used. The effect of flocculant type, charge density, and molecular weight on supernatant turbidity and solid settling rate was investigated as a function of flocculant dose, mixing rate and duration. All flocculants showed a parabolic trend with minimum turbidity and maximum settling rate. Anionic flocculants provided significantly higher flocculation efficiency. The anionic flocculant (AH3), with high molecular weight and low charge, demonstrated the highest flocculation performance, resulting in a turbidity of 9 NTU and a settling rate of 67 mm/min. The optimum flocculant dosage, mixing rate, and time for all flocculants were determined to be 2 mg/L, 150 rpm, and 1 min, respectively.

Phase change materials (PCMs) are becoming a key component in the design of next-generation textiles that can control temperature in response to ambient temperature for the goal of heat management. The high heat capacity of methyl palmitate (MP) was directly impregnated into porous diatomite in this study at four ratios (40%, 50%, 53%, and 55% by weight). The leakage test showed that composites with 53% and 55% MP exhibited leakage, whereas composites with 40% to 50% MP did not exhibit any leakage. Consequently, the cellulosic fabric coating method employed composites containing 50 wt% MP. A two-component silicone matrix that can be cured at room temperature was mixed with MP/Diatomite composite (MPDIA) in three ratios (10%, 20%, and 30% by weight). The resulting composite‑silicone mixture was then applied to the fabric surface. FTIR results showed no chemical interaction between diatomite and MP. The fabrics coated with MPDIA‑silicone mixture exhibited melting enthalpy (from 7.4 to 24.2 J/g) and freezing enthalpy (from 7.1 to 23.8 J/g). After 600 thermal cycles, no significant difference was observed in either the phase transition temperatures or latent heats of the coated fabrics. SEM-EDS analyses demonstrate that the coating layer maintains its durability on the textile surface, exhibiting resistance to 10 washes. Under solar exposure conditions, the thermoregulation performance of coated fabric with paste containing silicone and 30% MPDIA (CFMPDIA30) were experimentally assessed. Due to latent heat release, PCM-integrated fabric provided brief nocturnal heating while lowering peak daytime temperatures by up to 6.4 °C under intense solar radiation. A dominant and long-lasting cooling impact with a time-limited heating contribution was established by temperature difference analysis.

Polymer composites are widely employed in engineering and industrial applications owing to their tunable properties, lightweight structure, and enhanced performance achieved through the incorporation of fillers and additives. High-density polyethylene (HDPE) composites are of particular interest due to their chemical resistance and mechanical strength; however, their non-polar nature often results in weak interfacial bonding with polar additives. This challenge highlights the need for systematic investigations of filler-matrix interactions. This study examines the mechanical and electrical performance of HDPE-based composites incorporating calcite, graphite, ethyl vinyl acetate (EVA), elastomer, and crosslinker. The significance of this work lies in its multi-factorial approach, which evaluates the synergistic effects of multiple additives rather than relying on single-variable analyses. A total of twenty-six HDPE composite samples were fabricated using extrusion and injection molding processes designed through a statistical experimental plan. Samples were characterized by tensile strength, hardness, and electrical conductivity tests, alongside surface morphology analyses (SEM-EDS). Statistical evaluation was performed using analysis of variance (ANOVA) and response surface methodology (RSM) to determine the significance of parameters and their interactions. Results revealed that yield strength was best explained by the second-order model (quadratic), hardness by the first-order model (linear), while electrical conductivity did not fit the tested models. SEM-EDS further indicated poor dispersion and weak interfacial bonding between the HDPE matrix and additives. In conclusion, the findings emphasize the critical influence of additive type and proportion on the performance of HDPE composites.

For polyethylene terephthalate (PET) bottles, a material used for food packaging, light transmission and mechanical performance, particularly environmental stress cracking (ESC), are essential characteristics. For this purpose, following extrusion of PET/CaO granules, preforms were manufactured using the injection technique, and bottles were produced by a stretch-blow-molding process. With incorporation of calcium oxide (CaO), light transmittance increased by around 25%, and ESC went from 0.3 to 11 min. In addition, whereas acetaldehyde (AA) and carboxylic acid (COOH) decomposition values rose with increasing CaO content, diethylene glycol and isophthalic acid values did not significantly change. Moreover, the maximum crystallization temperature and crystallinity both exhibited an upward trend with the CaO content.

In this study, the effects of the extrusion process on the phase structure and shape memory properties of NiMn type Heusler alloy were investigated. For this, Ni55.5Mn25Ga18.5Mo2 alloy obtained by melting method in vacuum induction furnace was extruded at 950 degrees C, 1000 degrees C and 1050 degrees C, respectively. XRD analyzes of the obtained specimens were performed to compare crystallographic differences. Afterwards, metallurgical microscope and SEM photographs were obtained to see the phase structures of the specimens. Phase transformation temperatures were also determined by DSC analysis. In addition, EDS and MAPPING observations of elemental analysis were made. Then, Vickers micro-hardness analyses were performed to examine the effects of extrusion process on microhardness. As a result, the shape memory properties were negatively affected by the increase in extrusion temperature. Generally, with the increase in this temperature, the amount of high temperature phases increased significantly, as micro-hardness values slightly increased. In addition to this, martensitic phase structures decreased with increasing extrusion temperature and martensite and austenite transition temperatures could not be observed in DSC curves.

Due to the threats of lead to human and environmental health with Tin (Sn)- lead (Pb) solder alloys, efforts to develop lead-free solders continue. To adapt to different soldering areas, especially electronics, the search for alloys that can replace Sn-Pb has increased. The better the solders are in terms of thermal and electrical properties at the junctions, the better the performance of the circuit. In this study, changes in thermal conductivity, electrical conductivity, and melting behavior of 0.5-2 mass percent (wt.%) antimony (Sb) and 0.5-1.5 mass percent (wt.%) indium (In) addition to Sn-9Zn-4Bi alloy were investigated. Measurements of thermal and electrical conductivity with temperature were made by linear heat flow and four-point probe methods, respectively. The melting temperatures (peak temperature) of the alloys produced vary between 477.70 and 484 K (K). When the transition temperature, which is important in solders, is compared to Sn-9Zn-4Bi-[x]Sb (x = 0.5-2 wt %) and Sn-9Zn-4Bi-yIn (y = 0.5-1.5 wt%) alloys, it is the alloy with the lowest value with 13.80 K and the addition of 1 wt% Sb. The thermal and electrical conductivity values increased with the contribution of Sb and In. In addition, temperature coefficients for thermal and electrical conductivity were calculated. Electron and phonon contributions to the thermal conductivity were determined from the Wiedemann-Franz law. It was determined that electron contribution was higher for each alloy.

The purpose of this work is to improve mechanical properties of rigid polyurethane (RPU) composites used in traditional ceramic casting industry. Therefore, monofilament (mono) and fibermesh (fibril) polypropylene (PP) fibers with various lengths (3, 6, 12 and 18 mm) were incorporated to polymer matrix at different rates (0.5, 1.0, 1.5 and 2% by weight). Effects of fiber type and content on flexural strength, bending strength and compressive strength of composites were investigated. Surface morphology and thermal characteristics of composites were evaluated by SEM and TGA analysis, respectively. Bulk densities of specimens with and without PP fibers vary between 72,15-146 kg/m3. Compared to pure rigid polyurethane foam, bulk density of monofilament PP reinforced composites significantly increased and the highest density value (146,86 kg/m3) was reached in M6/2.0 sample. On the other hand, incorporation of fibrilmesh caused a decrease in bulk density. While the increase in percentage of mono PP increased flexural strength, the presence of fibril PP had a negative effect on strength. Compressive strength of all mono PP reinforced composites is higher than that of pure RPU, except for M6/0.5 sample. Besides, SEM analysis revealed that the presence of PP fibers generally reduced number of closed cells in composite structure. Experimental findings indicate that fiber type, content and length affect mechanical performance of RPU composites. In addition, it is possible to use mono PP fiber reinforced RPU composites as support apparatus in ceramic casting industry.

Statement of problem. Reusing the powder in selective laser melting machines after multiple cycles is a cost-effective procedure for dental laboratories. However, information on the metal-ceramic bond strength of the framework fabricated by using recycled powder is lacking.Purpose. The purpose of this in vitro study was to investigate how the bonding agent and repeated alloy powder reuse affected the metal-ceramic bond strength of cobalt chromium frameworks fabricated by using selective laser melting.Material and methods. Four square and 40-bar-shaped cobalt chromium frameworks were fabricated by selective laser melting. Half were produced by using virgin alloy powder (Group V; n(square)=2, n(bar)=20), and half with 30-times reused powder (Group R; n(square)=2, n(bar)=20). The particle size of each powder was measured by using scanning electron microscopy, and its phase composition was characterized by using radiograph diffraction. Each group was divided into 2 subgroups (Group W [Wash Opaque] and Group N [NP-Bond]) according to the brand of bonding agent used. After ceramic application, the metal-ceramic bond strengths were evaluated by using 3-point bend tests. The bonding agents' chemical composition was analyzed by using radiograph fluorescence. Bond strength data were analyzed by using a 2-way analysis of variance (alpha=.05).Results. Mean +/- standard deviation bond strengths did not differ significantly (P>.05) between Groups V (31.25 +/- 4.65) and R (30.88 +/- 4.78). Group W (35.34 +/- 1.78) had significantly higher bond strength than Group N (26.80 +/- 1.74; P<.001). Radiograph diffraction analysis found that the phase composition of all powders was similar. The bonding agent in Group W contained cerium, whereas, that in Group N did not. Conclusions. Metal-ceramic bond strength was unaffected by alloy powder reuse. However, the bonding agent brand may affect the bond strength of cobalt chromium frameworks fabricated by using selective laser melting. (J Prosthet Dent 2023;130:786.e1-e7)

Bu çalışmada enerji dağıtım hatlarında kullanılan kılıf malzemelerinin katkılandırılması ile alev geciktirici kılıf malzemesinin üremi üzerine çalışılmıştır. Şimdiye kadar yapılan çalışmalar incelendiğinde Halogen Free Flame Retardant (HFFR) olarak en çok kullanılan malzemeler Alüminyum Hidroksit Al (OH)3 (ATH), Magnezyum Hidroksit Mg (OH)2 (MDH) olarak karşımıza çıkmıştır. Bu malzemelere ek olarak Çinko Borat malzemesinin yanmazlık özelliğinden yararlanılarak, 3 alev geciktirici malzeme ile çalışma yapılmıştır. Çalışmaların çekme dayanımı ve yüzde uzama ve LOI (Limiting Oxygen Index) sonuçlarının optimum sonuçları ve en uygun kombinasyonları için deneysel tasarım yöntemi kullanıllanılmıştır. Deneysel tasarım yönteminin için ECHIP-7 programına tüm girdi parametreleri (çekme dayanımı ve yüzde uzama ve LOI) girilmiştir. Polimer matris olarak Lineer Düşük Yoğunluklu Polietilen (LLDPE) ve Etilen Vinil Asetat (EVA) kullanılmıştır. HFFR kılıf malzemesi için optimum bileşimin ağırlıkça% 40 Polimer, % 30 ATH ve % 30 MDH'ye sahip olması gerektiği sonucuna varılmıştır. Optimum parametre kriterleri göz önüne alındığında, kompozisyonda ZB kullanımına gerek olmadığı da görülmüştür. Optimize edilen reçete kablo kılıflamasında kullanılarak kabloya elektriksel, mekanik ve yanma testleri uygulanmıştır.

This study deals with the improvement of light barrier properties and stress cracking strength of polyethylene terephthalate (PET) packaging materials by incorporating calcium metaborate (CaB2O4). CaB2O4 powders were synthesized by the sol-gel method. After the extrusion process produced PET/ CaB2O4 granules, the preform arid bottle production was carried out by injection molding and blow molding. Compared to pure PET, UV transmittance is reduced (similar to 88%), and it is more effective at lower wavelengths (<800 nm). Similarly, the presence of CaB2O4 improved the environmental stress cracking performance of PET packaging materials. While the burst strength increased in the range of 0.05%-0.2% CaB2O4 concentration, it decreased at higher concentrations. The load-carrying capacity is approximately 109% higher than pure PET. Acetic acid (COOH) degradation increased with the incorporation of CaB2O4 particles, while isophthalic acid and diethylene glycol degradations did not change. The experimental data indicate that the photocatalytic degradation of the PET bottle is prevented significantly, and its mechanical performance is also improved with the incorporation of CaB2O4. Thanks to this novel product, the quality of food and beverages in PET packaging materials can be protected from the harmful effects of light, and the deformation of PET packaging materials can be prevented for various reasons.

This study is on polyethylene terephthalate (PET) compounded with magnesium borate (MB) (Mg 2 B 2 O 5 ) powders between (0.2–3.2% by weight) which were synthesized via sol-gel technique at laboratory-scale. The MB/PET composites were characterized in terms of chemical, thermal degradation, and mechanical properties. Their phases and chemical structures were identified by X-ray Diffraction and Fourier Transform Infrared analyses. The MB added into PET matrix significantly reduced PET degrading to acetaldehyde, carboxylic acids and diethylene glycol. However, while at 0.2 wt.% MB isophthalic acid (IPA) decreased and at higher MB concentrations there were higher IPA levels. The added MB increased the composites intrinsic viscosity (IV) compared to the pure PET. The highest IV (0.701 dL/g) was at the 0.2 wt.% MB/PET composite. Both T g and T m temperatures trended down up to 3.2 wt.% MB. Compared to pure PET, glass transition temperature (T g ) decreased to 80.4°C (at 3.2 wt.% MB) from 81°C, whereas melt temperature (T m ) decreased to 248.5°C (at 3.2 wt.% MB) from 249.4°C. The MB/PET composite tensile strength increased by 11.31% to a 60 MPa maximum at 0.2 wt.% MB compared to neat PET (53.9 MPa). However, at 0.4 wt. % and higher MB the dispersion was insufficient causing the MB powders to aggregate in the PET matrix, resulting in reduced tensile strength.

Bu çalışmada, ekstrüzyon yöntemiyle bor oksit (B2O3) farklı miktarlarda (kütlece %0,05–0,8) polietilen tereftalat’a (PET) katkılanarak önce PET/B2O3 granülleri sonrasında ise sırasıyla enjeksiyon ve gerdirme-şişirme-kalıplama yöntemleriyle şişe üretimi gerçekleştirildi. B2O3 içeriğinin artmasıyla PET kompozitin viskozitesi azalmış ve en düşük viskozite değeri %0,8 B2O3 konsantrasyonu için 0,385 dL/g olarak ölçülmüştür. PET kompozitlerin kristalleşme sıcaklığı (Tc), B2O3 miktarının artışına bağlı olarak yaklaşık 8,2ºC yükselmiştir. PET’in bozunması sonucu açığa çıkan izoftalik asit (IPA) üzerinde B2O3 katkısının herhangi bir etkisi görülmezken asetaldehit (AA) miktarında azalma, karboksilik asit (COOH) ve dietilen glikol (DEG) miktarında ise artış meydana gelmiştir.

The evaluation of wastes in various processes is an alternative to the production of innovative materials as well as eco-friendly. In the current paper, an industrial waste with high iron content (iron scale, F2O3) was incorporated into LDPE at different contents (5-20% by weight) and particle sizes (30-200 mu m). The raise of iron scale content and particle size under 10 N and 15 N loads caused an increase in the volume loss of the composites. The highest and lowest specific wear rates for all contents and particle sizes of iron scale under 10 N and 15 N loads were observed at 30 mu m and 120 mu m, respectively. The wear phenomenon occurred in the form of cracking and delamination mechanisms. As the particle size increased from 30 mu m to 200 mu m, the hardness value increased and the highest hardness (shore D = 49) was reached in the presence of 20% iron scale. The raise of iron scale content increased the elongation at break and did not significantly affect the tensile strength. The increase of particle size caused an increase in tensile strength, while a decrease in elongation at break was observed. The incorporation of iron scale did not significantly change the initial degradation temperature of LDPE and composites. Although there are partial differences at lower temperatures in terms of elastic and loss modulus of the samples, the general trend is a decreasing trend with the raise temperature. Overall, LDPE composites outperformed the pure LDPE in terms of mechanical and wear properties.

In this study, mechanical properties of CaCO3 reinforced Polypropylene (PP) matrix composite materials were investigated using the Digimat-Mean Field (MF) homogenization approach and ANSYS Finite Element Method (FEM). Simulation of CaCO3/PP composites, including 5, 15, 30, and 60 w% of CaCO3 was carried out by using a two-step multi-scale approach method. In the first stage, the micro-mechanic properties of the CaCO3/PP composite structures were obtained by using Digimat-MF by taking into account parameters, such as particle diameter, particle addition ratio, and interface binding between matrix and particle. As for the second stage, the Digimat interface was generated using the ANSYS Finite Element Method and macro-scale structural analyses of the CaCO3/PP composite structures were performed. In this way, the tensile and flexural strength of the CaCO3/PP composite structures were calculated by the ANSYS Finite Element Method. In addition, experimental analyses were carried out to approve the accuracy of the FEM results pertaining to the CaCO3/PP composites. The fact that the results obtained by experimental and simulation studies are very close to each other is an indicator of the accuracy of the simulation procedure applied in this study.

Polyethylene terephthalate (PET) bottles which are thermoplastic materials are used very commonly for the storage and transport of carbonated beverages. The most used production method for PET bottles is the Injection Stretch Blow Molding (ISBM) process. There is a variety of parameters affecting the produced PET bottles’ performances. Amongst these parameters, stretch rod movement, blowing pressure and preform surface temperature are the most important ones. Assignation of the optimal design parameters in PET bottles is taken into account. The effects of the parameters such as Preform Temperature (°C), Stretch Rod Position (mm) and Final Pressure (Bar) were analysed with the Taguchi method (TM), Grey relational analysis (GRA) and ECHIP. Body-weight (gr) (R1), Top Load (Pa) (R2), Burst Pressure (Bar) (R3), Stress Crack Resistance (Min.) (R4) and Tg (oC) (R5) were consiedered as performance parameters. The experimental design proposed by Taguchi involves using orthogonal arrays. An L9 orthogonal array was chosen for the procedure. Primarily, the performance parameters were optimized with the ECHIP Design of the Experiment (DOE). Thereafter, all of the factors were optimized together with TM, GRA and ECHIP.

The current study aimed to produce polyethylene terephthalate (PET)/takedaite (Ca3B2O6) composite bottles, an innovative packaging material with better performance. For this, Ca3B2O6 was firstly synthesized by sol-gel route and then it was incorporated to PET at five rates by extrusion. Finally, preform and PET bottles were produced by injection and stretch-blow-molding processes, respectively. The results showed that the use of Ca3B2O6 significantly improved the mechanical performance and UV transmittance of PET. Compared to pure PET, the load-carrying capacity and burst strength enhanced by 133.66% and 54.16%, respectively. Environmental stress cracking (ESC) time increased from 0.3 to 18 min at 0.8% Ca3B2O6 concentration. Moreover, UV transmittance (similar to 85%) of PET decreased to approximately similar to 18% in the visible region with the incorporation of 0.8 wt% Ca3B2O6. In terms of chemical degradation, Ca3B2O6 incorporation did not change the diethylene glycol (DEG) and isophthalic acid (IPA) rates, however it played an enhancing and reductive role in acetaldehyde (AA) and carboxylic acid (COOH) degradations, respectively. Accordingly, this novel product offers the opportunity to minimize the problems that may occur due to transportation/storage and photocatalytic degradation of food and beverages in PET packaging.

The present paper reports the pyrolysis behavior, kinetic, and thermodynamic parameters of paper mill sludge (PMS), which is a paper manufacturing residue and cannot be re-evaluated, at three heating rates (5, 10, and 20 °C min−1) under non-isothermal conditions. Ultimate and proximate analyses of the paper mill sludge were carried out. Kinetic and thermodynamic parameters were calculated using four model-free methods; Flynn-Wall Ozawa (FWO), Friedman, Kissinger-Akahira-Sunose (KAS), and distributed activation energy model (DAEM). High R2 values revealed that all models are compatible with TGA data. The activation energy calculated (101.01 kJ mol−1) from FWO was higher than the other three methods. Pre-exponential factor values ranged from 0.56 × 103 and 14.55 × 103 s−1 for all methods. Kinetic and thermodynamic findings will be beneficial in terms of the process design of PMS pyrolysis.

In this study, the change of mechanical properties by adding iron scales of different sizes into polypropylene (PP) was investigated. The iron scale was obtained from a steel production plant and adjusted to 30, 50, 90, 120, and 150 µm grain sizes. These iron scales were then added to the polymer material at a rate of 5% by weight. Wear and tensile strength tests were applied to the samples, which were formed in two different types. According to the results obtained, the wear and tensile strength of polymer material in all grain sizes were improved with an added iron scale. It was observed that the wear resistance of the composite material formed with the addition of fine-grained reinforcing element was the highest. Although grain size increased with increasing tensile strength, wear resistance did not increase. Besides, the friction coefficient was measured to be lower at increasing load. While the effective wear mechanism in pure polymer material is plastic deformation, this wear mechanism has not been found in composite materials with different grain sizes. In this study, it has been shown that iron scales have a positive effect on the mechanical properties of polymer composites.

This study is based on X-ray diffraction (XRD) and DSC analysis, Scanning Electron Microscopy (SEM) and Optical Microscope observations and Vickers Micro Hardness Test results with structural effect and phase transformations on NiMnGa shape memory alloys with different composition. The addition of different elements to the shape-memory NiMnGa alloys and the heat treatment of the alloys are extremely useful for improving the shape memory, magnetic, mechanical, chemical and other physical properties. The NiMnGaMo alloys were successfully obtained using a vacuum induction melting furnace and then homogenized by heat treatment at 950 °C for 2, 24 and 96 h, respectively. After homogenization, all samples were cooled in ice water. Crystallographic results calculated from XRD data were evaluated by comparison with the data obtained by DSC analysis, Scanning Electron Microscope (SEM), Optical Microscope and Vickers Micro Hardness Test Device. The results show that the alloy with a higher Mo amount has a smaller crystallite size and the L21 lattice volume increases with heat treatment time. The change on microhardness values were discussed with the change on the obtained lattice constants.

This study presents the characterization and thermal kinetic analysis of LDPE/carbonation sludge composites with different weight fractions (10%, 20%, 30%, 40% and 50%). Tensile, Young's modulus, hardness, morphological, thermal stability, flame retardant and dynamic mechanical properties of the produced LDPE/carbonation sludge composites were evaluated and compared. Analysis results revealed that the incorporation of calcium carbonate-based industrial waste into the LDPE matrix decreased tensile strength by 27.6%, while Young's modulus and hardness enhanced by 101.67% and 23.8%, respectively. A remarkable enhancement in both storage (Eı) and loss (Eıı) modulus were observed for LDPE/carbonation sludge composites compared to LDPE polymer. Furthermore, a significant improvement was noticed in the properties of composites containing 50% carbonation sludge due to the efficient dispersion and interface interaction between LDPE and carbonation sludge. Although the LOI value increases from 16 to 21% with the addition of waste, it is not sufficient in terms of flame retardant. For the thermal kinetic analysis, Coast-Redfern integral method was applied to three thermal decomposition zones of the composites. Accordingly, Ea and A values in zone II are higher than in zone I and III for all reaction models of composites. Overall, LDPE/carbonation sludge composites exhibited better thermal stability and dynamic properties than LDPE polymer.