Prediction of vibration induced damage in photovoltaic modules during transportation: finite element model and field study

The transportation of the photovoltaic (PV) modules involves excessive vibrations and shocks. These dynamic loads can crack the solar cells and glass of the PV modules. The cracks generated in solar cells during the transportation phase may not always have immediate implications on the electrical performance of the PV modules. However, in the long-run, cracks generated during transportation of the modules may propagate during operation in field due to wind load, snow load and thermal stresses. The propagation of cracks may create electrical isolation in the cells of a PV module, which can cause loss of electrical power. Therefore, it is important to minimize the damage in PV modules due to transportation and mechanical handling. In this work, PV modules have been transported in packaging following the industry practices to cover a distance of 270 km with accelerometers attached on several modules. Finite element (FE) modelling has been used to calculate natural frequency of vibration for the assembly of the PV modules by simulating the conditions close to the actual transportation experiment. This study shows that transportation makes the modules vibrate at their natural frequency. The first four natural frequencies of vibration calculated through the FE simulations match well with the peaks observed in the power spectral density profiles experienced by PV modules during transportation. Mode shapes corresponding to the first four natural frequencies have also been visualized to identify the contours with maximum displacement. It is hypothesized that out of all the cells, those falling within the contour of maximum displacement would have higher propensity for damage during the transportation. The results presented here can be useful for PV community to improve the packaging methodology, dimensions and material selection of the photovoltaic modules.

Past experience and future prospects for launching our country's small spacecraft from Plesetsk launch site

The paper provides an integrated analysis of the problem of the fast growing field of development and operation of Small Spacecraft (SS) constellations and participation of domestic launch site Plesetsk in solving this problem. It reviews the history of launches from Plesetsk, and describes the current status of work to build up and replenish SS-based orbital constellations. It describes major methods of SS launches. When describing multiple launches of SS on heavy launch vehicles it cites foreign practices of SpaceX Company, as well as lays down the prospects for development of our country’s heavy launch vehicles. As for the small-lift launch vehicles, it cites the experience of launching from Plesetsk of launch-vehicles Rokot and Soyuz-2 Phase 1v. For the super-small-lift launch vehicles, it cites the experience of USA and PRC, as well as our country’s development project of the launch vehicle Irkut, which is planned to be launched from Plesetsk, among other places. As for changes in the configuration of ground space infrastructure, the paper points out a trend towards processing SS at a single common processing facility (there is no need to construct processing facilities for each specific small spacecraft). The paper presents general trends in the system for operation of space facilities. The trends towards standardizing mechanical handling equipment in particular, and processing facilities in general, make it possible to lower development costs and speed up development schedules for advanced small spacecraft. Reducing small spacecraft processing time has a beneficial effect on the operational efficiency of the launch campaign, while the use of mobile checkout equipment makes it possible to quickly put together mobile and flexible processing facilities, the use of which will undoubtedly contribute to shaping the future of our country’s launch system. An important point made in the paper is the conclusion that in spite of our country’s lagging behind in super-small-lift launch vehicles, it has a significant scientific and engineering potential for developing this type of launch vehicles. Regardless of the value of other conclusions of the paper, the key point is that the current state of the ground space infrastructure facilities and the accumulated experience of specialists at Plesetsk make it possible to address the full spectrum of SS launch operations. Key words: small spacecraft, launch vehicles, ground space infrastructure, system for operation of space facilities.

Physical and chemical attributes of prickly pear cactus (Opuntia ficus-indica) varieties Copena, Pelon Blanco and Pelon Rojo

Objective: attest and compare the fundamental attributes for fresh raw cactus cladodes and its chemical constituent’s quality when dried and grounded for three varieties of prickly pear cactus “Copena”, “Pelon blanco” and “Pelon rojo”. Design/methodology/approach: measurements of the physical attributes and chemical constituents were made by using proved and reliable techniques. Data will aid to explore the potential for these cactus materials when being handled from basic to complex processes, considering its need for size and quality of storage and their effect when they interact with processing devices and handling apparatus for the new product being elaborated. Results: the physical attributes among the three assessed cactus varieties showed slight differences in their parameters, but length, wide and electric conductivity. While for their chemical analysis, cactus cladodes were chopped, dried and grounded. Chemical compounds showed slight differences between the three varieties, but Pelon blanco had a higher fat percentage and the lowest zinc and potassium concentration. None of the varieties had iron. Limitations on study/implications: there was no management on the prickly pear cactus production. The assessment of the cultivars’ attributes was as they were from the field. Stabilization of the chemical constituents of Pelon blanco could be necessary, according to the expected features of new products, or lead to a new line of by-products. Findings/conclusions: mechanical handling of raw cladodes around the premises is facilitated, and its uses and maintenance are fewer management costs. Flour from each variety was kept at around 10 % water content to safeguarding storage. Regard the protein and carbohydrates content, flour of the three varieties ensure integration with other compounds and guarantees new products with high protein content.

Design and analysis of elevator wire ropes

In this research paper design and analysis of wire ropes used in elevator have been presented. The main objective of this study is to find the best practices on handling wire ropes for safety and to reduce the downtime of elevators due to wire rope failures. Design calculations have been done to calculate the apt dimensions and design is constructed on Auto Desk inventor software and the analysis have been performed using Ansys. Two configurations of the wire ropes have been studied and from this result it can be concluded that the design of wire rope is possible to relieve mechanical handling and to improve the design of wire ropes making it more durable by possible inclusion of new materials which in turn increases the efficiency and life of wire ropes without compromising safety.

A Study on Toxic Effect of Chemicals and Control Strategies

Poisons are substances that can cause death, injury or harm to organs, tissues, cells and DNA usually by chemical reactions or other activity on the molecular scales, when an organism is exposed to a sufficient quantity. The objective of the study was to identify the toxic chemicals, to study their poisoning effect and present poisoning reduction strategies and then precautions. Analytical research method was used for conducting this research. This study is focused on the toxicity of major harmful chemicals such as hydrogen sulphide, carbon monoxide, carbon dioxide, chloroform, Sulphur dioxide, ammonia, formaldehyde, hydrogen cyanide, mercury, arsenic, cadmium and their compounds, catalyst, inert gases, insecticides, antidote which have been used in chemistry laboratories and in other different fields. Students from higher education to research levels are suffering from toxic laboratory chemicals. Workers in chemical industries are being intoxicated from poisonous reactants, intermediates and final products. Farmers are directly exposed to chemical fertilizers, insecticides, pesticides, herbicides, and fungicides. Different types of toxic irritant, sensitizer, asphyxiates, anesthetics, narcotics, systemic poisons, respiratory fibrogens, and carcinogens are mainly responsible for animal poisoning and environmental pollution. Poisoning from toxic chemicals can be controlled by the strategies like substitution, mechanical handling, process changing, suppression, segregation, ventilation, personal protection, medical supervision and biological monitoring. Immediate accidental poisoning can be managed by using respective antidotes and obeying specific precautions.

Paclobutrazol and phenoxaprope-P-ethyl potential as growth regulator in Carpet grass Plus®

Mowing is a fundamental management for turfgrass development. However, this operation has a higher cost, requiring alternatives to mechanical handling, such as growth regulators use. Thus, the objective was to evaluate the use of paclobutrazol and phenoxaprope-P-ethyl as growth regulators in Carpet grass Plus®. The experiment was performed in full sun, in the northwest region of São Paulo state, from January to March 2020. The grass used was planted in black plastic containers (50 x 17 cm, with a height of 15 cm, totalling 11 L of volume), previously prepared with a mixture of soil + sand (2:1). The experimental design was completely randomized, consisting of two doses of paclobutrazol (1.0 and 2.0 mL L-1) + control and two doses of phenoxaprope-P-ethyl (6.25 and 12.5 µL L-1) + control. Leaf chlorophyll index, digital image analysis and fresh leaf mass were evaluated. It was observed that for Carpet grass Plus®, there was paclobutrazol effect when used as a growth regulator, with the recommended dose of 2 ml L-1 due to its residual effect up to 35 days in reducing fresh mass, without changing the concentration of leaf chlorophyll and green colour. Phenoxaprope-P-ethyl, on the other hand, had an effect as a growth regulator for the studied species, when used in the dose of 6.25 µL L-1.

Useful Life of Ngancar Reservoir Due to Erosion and Sedimentation

Ngancar Dam is located in Ngancar Village, Batuwarno Sub district, Wonogiri Regency Central Java Province. This dam was built in 1944-1946 and is classified as an old dam in Indonesia which has a function to meet the needs of 1300 ha of irrigation water. Ngancar Dam is a type of rock fill dam with a soil core, has a height of 19.40 m above the riverbed and 25.40 m above quarry. The length of the dam peak is 181.00 m and the width is 5.00 m while the reservoir volume at the normal water conditions is 1.64 million m3 . Because the Ngancar Dam has been operating for a long time then required the evaluation on the service age of the reservoir due to sedimentation so that it effects on the operating pattern and safety of the dam. Based on the results of hydrological analysis and reservoir bathymetry analysis obtained the information that the reservoir sedimentation rate equal to 4,266.08 m3 /year or 11.9 m3 /day and this requires mechanical and non-mechanical handling efforts to reduce the sedimentation rate

AUTOMATIC LIQUID FILLING MACHINE.

A conveyer system is a common piece of mechanical handling equipment that moves materials from one location to another. Our project uses this technology for filling any desired liquid into a container one after another continuously with the help of Arduino nano. This equipment will be useful in industries for large scale production of bottled items. Also, this same equipment but of small size will come in handy for domestic usage . This report consists of entire details of the method of making and assembling the “AUTOMATIC LIQUID FILLING MACHINE” along with the programming of controlling component i.e, Arduino nano.

Relevant criteria for the selection of cryotubes. Experiences from the German National Cohort

Background The storage of different biomaterials over long time periods is one of the main requirements of biobanking ensuring that modifications in the composition or any other change of the biomaterials have to be avoided. In the German National Cohort samples from around 200,000 participants are processed and stored long term. Methods A tender for cryotubes and racks was performed in 2013 setting up several characteristics that were judged against each other. Tubes and racks were evaluated regarding the performance and handling in connection with the main biorepository. With a 5-year experience using the selected tubes we are able to reflect some of the criteria of the tender. Results At the end of the decision, the former company FluidX, in the meantime taken over from Brooks (Brooks Life Sciences, Manchester, UK), received the order. The experience with the external testing of the tube was useful. Conclusions Overall, the experience with the cryotubes is good and their mechanical handling at the different sites is routine in the meantime. There are some aspects that we recommend for future tenders. Further research is necessary to learn more about the cryotubes and the labware in general in the field of biobanking to store our samples as safely as possible.