This case study aims at assessing and understanding the level of ergonomics in manual material handling tasks (loading, granite cutting, concrete mixing, brickwork, and plastering) of civil construction workers and dump truck drivers working in Indian opencast mines. The study involves the determination of the level of musculoskeletal disorder and predicting the most affected body parts due to incorrect working posture. The comprehensive methodology involved in this study includes rapid upper limb assessment (RULA) and rapid entire body assessment (REBA) techniques to find the risk involved in the working posture of the construction workers and dump truck drivers. The study showed that posture adopted in civil construction work and dump truck operators (loading and unloading task) are ergonomically incorrect and may cause musculoskeletal disorder (MSD) related problems in the future. This study also showed that the trunk and wrist are the most affected parts of the body in construction workers and the neck and wrist in case of the dumper operator while performing different tasks.
The research paper reports on the processing of titanium carbide (TiC) strengthened aluminium metal matrix composite using a stir casting method. Al 6061 and TiC were used as starting materials for synthesizing Al-1.5TiC composite in a resistance furnace. The stir casting technique was followed owing to its simplicity and economic benefits. Microstructural studies were carried out using image analyser and micrographs revealed even dispersal of reinforcement in the alloy, while energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) studies confirmed the presence of corresponding elements and phase in the composite.
A desirable benchmark should be complete from all aspect, holistic in nature and conceptually universal as well as acceptable. This work reviews the related literature and conclude that different types of benchmarking methods are used in different organizations and institutions. The everincreasing demand for continuous improvement of quality and performance in any field or organization leads to benchmarking. Benchmarking is an effective technique, which supports innovative ideas. The present study aims to provide an inclusive review of performance benchmarking. In this work, different types of benchmarking techniques are categorized, and their drawbacks and the research trends are provided to assist researchers and practitioners in conducting new research in this area. A new benchmarking methodology has been suggested which could be acceptable universally for all the heavy earthmoving machines (HEMMs) which provides numerical benchmarked value which can be easily used for the comparison purpose
In order to investigate the effect of different perforation angles (the angle between the perforation direction and the maximum horizontal principal stress which is also called the preferred fracture plane (PFP)) on the fracture initiation and propagation during the hydraulic fracturing of highly deviated well, laboratory experiments of the hydraulic fracturing of the BZ25-1 oilfield had been carried out on the basis of non-dimensional similar criteria by using 400mm3 cement cubes. We built the geometric model of the hydraulic fracturing fractures which considered the influences of the wellbore azimuth (the angle between the wellbore axis and the PFP), the perforation angle and the well deviation. The results showed that: the perforations in the PFP produce plane fracture; the fractures initiate from the perforations at the upper side of the well hole and then turn to the PFP when the perforation angle is 45°; when the well deviation angle and the perforation angle are both larger than 45°, the fracture initiates difficultly from the perforations at the lower side of the well hole, and multi-fractures easily initiate; when the perforation angle is 90°, multi-fractures initiate, such as twisting fracture, plane fracture, horizontal fracture and T-shape fracture, in addition, the fracture cannot initiate from the perforation tunnels; the larger the well deviation angle is, the easier is the multi-fractures initiation. Moreover, it is easier to result in micro-annulus which makes the fractures more complicated during the hydraulic fracturing of highly deviated well when the perforation angle is not along with the PFP. Oriented perforating technology should be applied in highly deviated well to obtain the big single plane fracture.
L’univers numérique s’est développé si rapidement que la question de la confiance peut paraître secondaire. Cependant, à mesure que les usages se diversifient, des comportements viennent amoindrir la confiance en cet espace (fraude, usurpation d’identité, cyberharcèlement). En outre, la collecte massive de données personnelles opérée par les services numériques interpelle. Par ailleurs, la cybercriminalité, la surveillance étatique des communications entravent également la confiance en ligne. Dès lors, un tel espace interroge les mécanismes qui produisent et entretiennent la confiance. Si ces mécanismes de confiance ont dans un premier temps imité les mécanismes classiques, l’univers numérique a progressivement produit des mécanismes de génération et de gestion de la confiance propres, en s’appuyant sur la nature de ce qui le caractérise, l’organisation réticulaire et le traitement des données. Dès lors, l’architecture du tiers de confiance, quelle qu’en soit sa modalité, pose elle-même question et débouche sur l’idée qu’une architecture de réseau, par conception, par elle-même, peut générer la confiance dans les échanges.
Metal Inert Gas (MIG) welding is an advanced type of welding process where a fusion of gas welding and arc welding is used with shielding component (CO 2 ) at welding zone and brass coated stainless-steel wire is used as electrode and the feed for joining material (304 stainless steel) is automated which can mostly utilized in mines and metals industries for specific uses. This paper includes parametric influences like applied voltage (V), current (I) and gas flow rate (lit./min) on surface roughness (R z ), width of bed thickness (WOBT) and hardness. The article also consists of the development of mathematical models and analysis of variances (ANOVA) for validation to fit of experimental data and developed models. To find out the single as well as multi objective optimization for minimum surface roughness (R z ), minimum width of bed thickness (WOBT) and maximum hardness through desirability function analysis using response surface methodology (RSM) during welding of 304 stainless-steel thin plate by MIG process. This paper also validated the test results at optimal conditions of 26V, 120amp and 21 litter/min gas flow rate and achieved maximum hardness of 97, WOBT of 5.57mm and minimum surface roughness (R z ) of 7.65 m m.
D’un côté, l’intelligence artificielle est à la mode : les principaux acteurs politiques et économiques engagés dans le développement des technologies numériques la promeuvent avec ferveur. D’un autre côté, l’intelligence artificielle fait débat : certains vont même jusqu’à proclamer qu’elle n’existe pas. L’imbroglio est important. L’intelligence artificielle est-elle un mirage ? Dans cet article, nous verrons que non. Nous montrerons plus exactement comment s’est construite cette confusion qui caractérise l’intelligence artificielle, dont l’existence est bel et bien réelle. Pour ce faire, nous soutiendrons que l’intelligence artificielle est une discipline scientifique qui, dès le départ, a été couplée à une pratique économique produisant un déséquilibre entre recherche fondamentale et recherche appliquée. Nous ajouterons alors que c’est précisément ce déséquilibre qui est à l’origine du flou autour de cette discipline scientifique, et, plus largement, de l’instabilité caractérisant son évolution.
As is well-known, hydrocarbons resources are finite and once extracted they are put to use and cannot be replaced. So, what do governments do when faced with geological data that tells them their resources might reach a peak in only a few years or worse, that they have already began to decline? How can these resources be used to transform positively the economy and society if they are only going to be producing benefits for a very few more years? This question gives a new flavour to the traditional concerns that governments have about attracting scarce investment capital. Some of the very largest investors will look at the geology and say: not for us, thank you. Are there any lessons from countries around the world that might help to shape government policy in response to these pressures? There indeed many examples to draw from however, this paper will focus on the UK experience and lessons that can be drawn from this experience. In this respect, this paper attempts to summarise a few of these experiences and offer some summary recommendations to governments in Asia and Africa that may wish to consider the policy implications of this inevitable development. It draws on the CEPMLP/Hub Databank of Country Laws and Regulations.
The consumption of hydrocarbon is increasing day by day. A number of technologies are being used to meet out the demanded quality. The drilling and blasting is a cheapest way to exploration and excavation in mining industries. The blasting creates excessive amount of energy in different form of ground vibration as shaking of Earth, flyrock, removal and transportation of overburden rockmass and other noise. Blast-induced ground vibration has some adverse effects on surrounding environment as well as community living nearby the opencast mine. The study was conducted at opencast coal mine in Chhattisgarh. A total number of 32 data sets have been measured with different parameters such as; maximum charge per delay (MCPD), observation distance, charge length, spacing, burden, blast hole depth, hole diameter, etc. as well as peak particle velocity (PPV), frequency and peak vector sum (PVS). In present study, main focus on measurement and prediction of peak particle velocity by different predictor model (USBM, Indian Standard, DGMS) and multi-variate statistical regression analysis (MVSRA). Simple linear regression model (SLRM) is used to determine the site characteristics constants. The constants are used to establish new prediction model equations among different parameters. Finally, assess the blast induced ground vibration on the basis of measured and predicted peak particle velocity.
Diesel engines efficient and economical large, but at is large in size and non friendly environmental. LPG is available at a lower price than other fuels and environmentally friendly. One of the important research topics that have been updated is the use of LPG in diesel engines. The LPG has a high heat value, and its gaseous state makes mixing with air simple and has perfect redound of combustion to increase the power output also the LPG helps to fully consume the fuel and thus reduces emission and helps to harvest the total energy found in the fuel. It was designed a new Electronic Control Unit (ECU) and used of the LPG injection timing and duration while opening the air intake valve into the combustion chamber and a magnetic sensor is installed on top of a single cylinder diesel engine with air-cooled. The test engine was run in four fuel mode the start was used is D-100, after that the fuel was used LPG-25, LPG-50 and LPG-100. The test was under loads 0%, 25%, 50%, 75% and 100% at different speeds 1000, 1500 and 2000 rpm. At the engine speeds 1000, 1500, 2000 rpm compared with D-100 fuel, the thermal efficiency was better at using LPG-50 fuel were increased about by (0.99%, 0.92%, 1.29%) and bsfc were decreased as (9.81%, 9.4% and 9.68%) respectively. A decrease in emissions, NOx, HC, CO and CO2 was observed in all operating modes with LPG and the best emission reduction situation is LPG -50.
The basic task of the development of seismic fine tectonic interpretation is the interaction analysis of threedimensional seismic data interpretation and real drill results, timely guide the well position adjustment and improve the success rate of drilling the reservoir. Aiming at the requirements of the development of the seismic geology task in the north Shen 150 area of the Rongshengbao sag, the technical combination suitable for the characteristics of this area has been worked out, and good geological effect has been achieved. First, the seismic data were evaluated. Second, the fine calibration was carried out. Third, the microstructure was studied. Finally, the concrete application of Shen 150 was studied. The results of 3D seismic fine structure interpretation is more truly reflect the shen 150 block of the underground structure in the study area of fault and the shape of the distribution situation, in order to improve the high steep complicated structure area drilling success ratio provides the reliable data.
The use of diesel engine powered equipment in underground mines across the globe has been increased considerably in the recent past to enhance the productivity and safety standards. However, the extensive use of diesel engine powered equipment caused severe health hazards because of the exposure to diesel particulate matter (DPM) and toxic gases discharged from the exhausts of these equipment. NIOH and IARC, USA, reported diesel exhausts including DPM are suspected as human carcinogen. The number of diesel equipment deployed in Indian underground mine has also increased exponentially, which resulted into significant level of DPM exposure. There have not been any comprehensive study on the exposure of DPM as well as any stipulation in the current mine safety legislation in India so far except a guideline from DGMS. The concentration of DPM depends upon many factors such as ventilation, engine designs, maintenance, types of fuel, condition of roadways, exhaust treatment arrangements etc. In the present study, field investigations were accomplished in the three underground metalliferous mines. Different parameters like quantity of air, power and life of engine and gradient of roadways were taken as independent variables to predict the concentration of DPM. Multivariate regression analysis was carried out for establishing the relation between DPM and these independent parameters, and a significant empirical equation has been derived. Thereafter, DPM values were measured by Airtec DPM monitoring instrument and the values predicted from the multivariate regression model and measured values from the instrument were validated through chi square test.
Whenever gas kick occurs, gas flows in mixture with the flowing drilling fluid or migrate upwardly when drilling fluid is suspended. When wellbore temperature and pressure are higher than the critical temperature and pressure of natural gas, natural gas is in a supercritical state. In the process of gas migration along the wellbore, gas volume will gradually increase due to the decrease of wellbore temperature and pressure. At the critical point, phase behavior changes and gas volume increases very rapidly, which can bring great harm to well control; what is worse, it may lead to well blow out. Therefore, it is of great significance to analyse the effects of phase change characteristics of the supercritical fluid on well control safety. Due to the huge advantages and strong adaptability of Lattice Boltzmann method (LBM) to solve gas-liquid two-phase flow problem with complicated and changeable phase interface, wellbore gas-liquid phase transition based on inter-particle interaction of LBM method is researched in this paper. Simulation results show that different initial densities of mixed fluid have significant influence on gas and liquid phase distribution after phase transition. Continuous gas is formed in phase change position of a wellbore when initial density of mixed fluid is less than the critical density. And gas change in phase behaviour migrates along the wellbore as bubbles when initial density of mixed fluid is greater. Research results not only improve the understanding of gas-liquid phase transition mechanism, but also can provide some valuable attempts to promote the application of LBM method in wellbore gasliquid two-phase flow.
Dans cet article, sont passées en revue les propriétés remarquables des ondes térahertz (THz), qui les rendent appropriées pour une grande diversité d’applications, ainsi que les diverses technologies nécessaires pour la mise au point de sources et de détecteurs dans la perspective d’une industrialisation de ces applications. En conclusion de cet article, sont donnés quelques éléments relatifs au marché du THz et un bref aperçu de la situation de la R&D en France.
La sonochimie, ou l’utilisation des ultrasons de puissance pour des applications en chimie, est fondée sur les effets physico-chimiques engendrés par la cavitation acoustique. Cette technologie de rupture fait l’objet de recherches académiques qui ont démontré récemment de nouvelles efficacités et réactivités, ainsi que des apports en termes de chimie verte, dans différentes applications en matière de chimie organique, de catalyse, de matériaux, de polymères, d’extraction ou encore de remédiation environnementale. La démonstration de procédés sonochimiques innovants à grande échelle permettrait de montrer le potentiel, peut-être sous-exploité, de la sonochimie pour l’industrie.
The SF double-wall oil tank has an interstitial space with the thickness of 0.1 ~ 0.2 mm between the steel inner tank and FRP outer tank, and is equipped with a leak detection device to monitor the interstitial space for 24 hours. If internal structure of the interstitial space is designed unreasonably, the leaking liquid will be difficult to flow to the bottom of interstitial space, so that the leakage detection device cannot detect the leaking problem in time, leading to security risks during the operation process of double-wall oil tank. In this paper, the volume of fluid (VOF) model and the PISO algorithm are used to study the flow characteristics of the leaking liquid in interstitial space of double-wall oil tank based on FLUENT software. In order to reduce the computational complexity, the structure of the interstitial space of the SF double tank is simplified reasonably. It is believed that this research is valuable for the optimal design of the interstitial space structure of double-wall oil tank.
