Micro-Concentrated Photovoltaics Based on Cu(In,Ga)Se2 Microcells: An Optical Study

Micro-concentrated Cu(In,Ga)Se2 (μCPV-CIGSe) solar cells offer the potential to reduce the consumption of raw materials to a great extent while maintaining high efficiencies. A theoretical model of μCPV-CIGSe solar cells, consisting of hexagonally spaced micro-CIGSe solar cells embedded in the low-index dielectric matrix and micro-sized lenses placed right on top, is proposed for optical study. It is discovered that micro-lenses enable to effectively concentrate the incident light due to the inherent nanojet phenomenon, and the μ-CIGSe absorbers trap the penetrated light within absorbers arising from wave-guided modes. The two effects co-contribute to an optimized absorption for μCPV-CIGSe solar cells with a μ-CIGSe absorber diameter of 800 nm and a pitch of 1500 nm. Short-circuit current density reaches 36.5 mA/cm2 and accounts for 98.8% compared to their plain counterparts without lenses, corresponding to an absorber material saving by a factor of 3/4. Notably, a large contacting area between lenses and CIGSe solar cells are recommended for an improved angular tolerance. Those findings will recommend design principles for further experiments.

Investigation of a Possible Material-Saving Approach of Sputtering Techniques for Radiopharmaceutical Target Production

Magnetron sputtering (MS) is a relatively new deposition technique, which is being considered among the cyclotron solid target (CST) manufacturing options now available, aiming at the medical radioisotopes yield for radiopharmaceutical production. However, the intrinsic high material losses during the deposition process do not permit its use with extremely expensive target materials, such as isotopically enriched metals/oxides. In this study, R&D technology for a new recovering shield is instead proposed to assess the dissipation of target material during the sputtering processes and, thus, an estimate of the material recovery that may be feasible and the related amount. The weight-loss analysis method is used to assess the material losses level inside the chamber during processing. In all tests carried out, a high-purity copper (99.99%) was used as a target material. As a result of this study, the material distribution for both magnetron and diode sputtering depositions can be calculated. The feasibility of the ultra-thick coatings growing, devoted to CST production, is demonstrated.

IMPLEMENTATION OF CIRCULAR DISCONTINUITIES IN CFRP BUMPER BEAM FOR MATERIAL SAVING: A CASE STUDY

An automotive bumper system consists of an energy absorber, fascia and bumper beam. Among them, the bumper beam is the main component contributing to the overall weight of the vehicle. The bumper beam absorbs the kinetic energy during an accidental collision by deflection in low speed impact and by deformation in high speed impact. Carbon Fibre Reinforced Plastic (CFRP), being an extremely strong and lightweight composite, is a good candidate for bumper beam material. Earlier used in high performance cars CFRP is nowadays being promoted to be used in passenger cars also. The reinforcement beam is the vital part which ensures safety and needs to be validated through Finite Element Analysis (FEA). Therefore, the double hat bumper beam is impacted with a cylindrical impactor and analyzed in Abaqus. In this paper the bumper beam is analyzed after weight reduction by putting circular holes for material saving. Further the effect on cost of production is calculated. Above all, material saving reduces carbon footprint.

On the Relation between Strength and Stiffness of Cable Tray

In order to realize the optimal design of the cable supporting system for the purpose of material saving and energy saving and green manufacturing, the strength-stiffness ratio is proposed in the paper in nondimensional form, which defines quantitatively the relation between the static load strength and stiffness of the cable tray. On the premise of ensuring service safety, the correlation between the strength and stiffness of the cable tray under static load is discussed extensively through the theoretical analysis of the mechanical model. The weakest link in the carrying capacity of the cable tray as well as the issue that needs to pay attention is proposed in the process of design and the test of the cable tray. A reasonable strength-stiffness ratio will help to make full use of the potential of material strengths. The value of the strength-stiffness ratio is obtainable by means of the finite element method or by the loading test of the cable tray. It is shown through the analysis that the value of the strength-stiffness ratio being setting in the range close to but less than 1 will make comparatively reasonable material utilization and will help the deflection test going smoothly to obtain a relatively safer allowable working load for the cable tray.

New material-saving technologies of pipe rolling on pilgrim units

In this work, based on the analysis of the process of hot pilger rolling of pipes of a wide range of sizes and grades from a round continuous cast billet, new and improved existing metal-saving technologies have been developed to reduce metal losses in the pilger head.Using scientific and patent sources of information in the field of pilger rolling and its mathematical modeling with the calculation of tables for rolling pipes of a wide range of sizes from a round continuous-cast billet with a diameter of 385-470 mm, metal losses into technological scrap on a pilgerstan are determined: a seed and a pilger head.On the basis of the results of the theoretical determination of metal losses in the process scrap on the pilgerstan: the seed and the pilger head, a forecast was made to reduce the weight of the pilger head, which was used to develop new material-saving technologies for pilger rolling of pipes, both thick-walled with D / S = 6 - 12.5, and thin-walled with D / S = 12.5 - 40. Metal losses in the pilger head are the main factor of increased metal consumption coefficients on pilger units, which reduces their competitiveness in comparison with other units when using round continuously cast billets as a starting material.The forecast for the reduction of metal losses in the pilger head made for the first time makes it possible to estimate the reserves for reducing the mass of the pilger head both by eliminating the underflow of the liner and trimming of the pipe end adjacent to the pilger head, and by means of individual parts of its profile part and predicting its decrease to the minimum possible size, ensuring the removal of the pipe from the mandrel using a gate device.To reduce the weight of the pilger head when rolling thick-walled pipes, it is recom-?ended to use improved technologies for butt-end rolling and rolling of the pilger head on the free section of the mandrel.The results of the studies and the proposed new material-saving technologies can be used on pilgrim units when rolling thick-walled (D / S = 6 - 12.5) and thin-walled (D / S = 12.5 - 40) pipes of a wide range of brands (carbon, alloyed, highly alloyed and special) from both continuous casting machine and forged and centrifugally cast billets, as well as ingots.

Energy and material saving technologies for construction of main pipelines for oil and gas transportation

Based on the study and analysis of technologies and technical means for transporting oil and gas through main pipelines, energy and material-saving methods of their construction are scientifically substantiated. A method for designing trunk oil and gas pipelines with variable wall thickness is proposed, which is possible under the conditions of the current interstate standard GOST 31447-2012. The technique is based on the use of methods of mathematical and statistical modeling and construction of a multifactor experiment and processing of experimental data. Based on the results of the construction of the model, the optimal parameters for the construction of pipelines were found, new technical solutions were proposed that would significantly reduce the energy and material consumption of laying pipes during one run, i.e. between transfer pumping stations.

Inclusion Modeling of Bucket Elevator Conveyor Chain Links

Inclusions, pores, and cracks which are defects in materials are important in determining the structural integrity and durability of components. Modeling accurately, these defects are hence of interest to both theorist and the practitioner. CAD models were designed using Autodesk Inventor software, and simulation was performed using ANSYS academic software. Material saving in design of conveyor chain links has gained popularity, and this has led to the introduction of necks in its geometry. However, the effect of necking on various parameters was not considered. Also, inclusions which are defects in material are known to have adverse effect on the conveyor chain link. It is, therefore, imperative to predict numerically, the effects that inclusions and necking have on conveyor chain links This paper focusses on modeling nonmetallic inclusions and also tests various models of different neck radii using the finite element method so as to predict its effect.

Research on Implementation and Evaluation of Highway Green Construction

This article analyzes how to implement green construction in highway construction around six aspects of highway green construction management, construction material saving, water saving, energy saving, land saving and environmental protection. According to the control and non-control work, this article studies how to evaluate the implementation effect of highway green construction from the aspects of sub-elements, sub-batches, sub-project categories and sub-stages. The proposed implementation plan, evaluation method and evaluation organization of highway green construction can provide technical reference for the implementation of highway green construction.