Short Production Cycle Research Articles

Dynamics and sustainability of urban and peri-urban vegetable farming in Yaound City, Cameroon

In the context of rapid urbanisation of Cameroon, it is estimated that 70% of the total population will be dwelling in urban centres by 2060. Meanwhile, vegetable production has become an important economic activity for the urban and peri-urban poor because of its shorter production cycle. Thus, this study aims at describing the dynamics of the changes and sustainability within vegetable production systems in urban and peri-urban areas. A survey was conducted among 185 vegetable farmers and 184 non-vegetable farmers in urban and peri-urban areas of Yaounde using a structured questionnaire. Descriptive results show that vegetable production is concentrated in densely populated areas with underpinning socio-economic characteristics. On average, vegetable producers are married (70.0%), educated (94.0%) and mostly young adults (24.0%). Most (70.0%) of the respondents have vegetable farming as their main source of income. The most dominant cropping system is the strip cropping system between traditional vegetables. The results of the sustainability analysis show that the profitability of vegetable production decreases with population density. While mulching, crop rotation and the application of organic manure increase with population density, land fallow is observed to decrease. The perceptions of vegetable producers and non-producers towards vegetable production are broadly similar. Finally, more than half of vegetable producers (53.0%) will not be able keep working on their plots in the next 10 years. Therefore, urban policy planners should take into account vegetable production when elaborating master and zoning plans to better preserve and integrate it as part of the urban development plan. Key words: Urbanization, vegetable production system, sustainable agriculture, Yaounde

Simulation and optimization of microlens hot-melting fabricating process based on finite element method

As an important optical element, the microlens array has received more and more attention. Due to the advantages of a short production cycle, low cost, high efficiency, and easy to transfer, the photoresist hot-melting method has been widely used to fabricate microlens. Fabricating microlenses with large aperture and curvature radius are the basic requirements to ensure image quality. However, due to the limitations of photoresist material properties and the hot-melting process, the shape of the microlens is not easy to control. In this paper, the finite element fluid simulation software Fluent was used to simulate the microlens hot-melting fabricating process. Through the simulation, we could understand the formation process of the microlens. By multiple groups of simulation comparison, the key parameter in the formation of microlens was discussed. Besides, the simulation result shows that when a layer of residual photoresist is left around the original photoresist cylinder, microlens with larger diameter can be easily obtained. The experimental results are in good agreement with the simulation results. The comparison imaging experiment also illustrates that the microlens fabricated by the improved process has better imaging ability. Through simulation, this paper not only explains the mechanism of the hot-melting method, but also optimizes its process. The related research could expand the application range of the hot-melting method in the fabrication of microlens.

Aquaculture as a tool to support goby‐fry fishery? Current knowledge on biology and ecology of the red‐tailed goby Sicyopterus lagocephalus

AbstractSicydiinae species are amphidromous gobies, adults spawn in freshwater, whereas free embryos undergo a pelagic open sea phase. Post‐larvae or juveniles are caught for human consumption when entering in freshwater after their pelagic larvae life in seawater. Such goby‐fry fisheries are existing since centuries and widespread in tropical areas over the world. There are uncertainties related to caught volumes and trends but, overall, go‐fry fisheries are declining and their sustainability is questionable. Aquaculture is a potential tool in conservation and management of wild goby stocks. Among Sicydiinae species, the red‐tailed goby Sicyopterus lagocephalus is the most spread and used as a model species in numerous works involving amphidromous fish. The aim of the study was to evaluate the potential in aquaculture of the red‐tailed goby through the analysis of the literature available on this species. We found that this species has some assets to be a potential candidate for aquaculture such as a short production cycle and a high fecundity as well as potential high market values. Nevertheless, given the small size at hatching and the long pelagic larval life, larval rearing is likely to be a challenging rearing phase but appears to be feasible based on past experiences with other goby species. Throughout the paper, we provided recommendations for future research in red‐tailed goby aquaculture.

Enhancing the nutritional and functional properties of Pleurotus citrinopileatus mushrooms through the exploitation of winery and olive mill wastes

Treatment and disposal of wineries and olive-oil mills waste is usually associated with complex processes, which are often of limited wide-scale applicability. Olive-leaves plus two-phase olive mill waste (OLW) or grape marc plus wheat straw (GMW) were assessed as substrates for the cultivation of the choice edible mushroom Pleurotus citrinopileatus. GMW led to increased mushroom biological efficiency and shorter production cycles. Antioxidant activities, triterpenic acids, free amino acids, lovastatin and ergosterol were significantly higher in fruitbodies from GMW; the latter compound was positively correlated with squalene concentrations in substrates. Glucans, resveratrol and fatty acids content showed minor differences among mushrooms from the three substrates examined, whereas ergothioneine was significantly higher in fruitbodies grown on OLW. High correlations were noted for oleanolic, ursolic and amino acid content in mushrooms and their respective substrates. Moreover, FTIR spectra revealed variations in fruitbodies content in bioactive compounds which were associated with the substrates used.

Comparative Study of Surrogate Modeling Methods for Signal Integrity and Microwave Circuit Applications

With a short product cycle as we see today, fast and accurate modeling methods are becoming crucial for the development of new generation of electronics devices. Furthermore, increased complexity in circuitry and integration compounds design iteration and the associated, high-dimensional sensitivity analysis and performance optimization studies. Therefore, black-box surrogate models replacing the actual circuitry offer an attractive alternative for more efficient design iteration, optimization, and even direct Monte Carlo analysis. In this article, surrogate models built using nonparametric Gaussian process (GP) are presented. A robust framework based on probabilistic programming is used for training GP models. Other methods, such as partial least-square regression, support vector regression, and polynomial chaos, are used to compare with the performance of GP. Three design applications, a high-speed channel, a millimeter-wave filter, and a low-noise amplifier are used to demonstrate the robustness of the proposed GP-based surrogate models.

Discussion on the Flexible Manufacturing and Operation Strategy Model for a Machine Tool Component Company in Taiwan

Recently, many manufacturing industries have been facing challenges such as rising material costs, small-volume and large-variety products, shortened production cycles, increased labor costs and longer after-sales service times, which is a very tough challenge for most small and medium-sized component manufacturing suppliers. In addition to the current hot topics in the manufacturing industry - Smart Manufacturing (Industry 4.0) and lean production management, if small and medium-sized enterprises are not able to adjust the pace of manufacturing timely and find a suitable production model, they will soon be overwhelmed by the torrent of the era of speed and accuracy. In the face of the dramatic changes in the industry structure, the company can deploy the global expansion of overseas customers in advance, and adjust to apply and implement a flexible manufacturing model system through the introduction of the Industrial Internet of Things and flexible manufacturing production management. In order to meet the market needs, the manufacturing industry is gradually oriented towards customized production and the rapid development of new products. To meet such stringent requirements, flexible manufacturing becomes one of the necessary ways for enterprises to consider their development models. Therefore, the efficiency and reliability of work can be improved through the Industrial Internet of Things that facilitates machine-to-machine communication, cloud-based big data and learning and imitations of smart robots. This study is an in-depth study of a company that is currently in the process of digital transformation, collecting relevant information and reviewing the analysis to find a suitable smart manufacturing solution for the company and to explore the impact of the COVID-19 pandemic on the strategic development of the company. The findings can provide a significant reference for homotypic companies in the development of their business strategies.

Study on Geometry, Dimensional Accuracy and Structure of Parts Produced by Multi Jet Fusion.

Multi Jet Fusion (MJF) is one of the newest additive manufacturing technologies for polymer powders, introduced in recent years. This fully industrial technology is gaining big interest as it allows fast, layer-by-layer, printing process, short production cycle, and very high printing resolution. In this paper, twelve thin-walled, spherical PA12 prints were studied in terms of geometry, dimensional accuracy, and fracture surface characteristics. The various characteristic features for MJF prints were observed here for parts produced according to four various print orientations and having different thicknesses, i.e., 1, 2 or 3 mm. The study showed that MJF technology can print such difficult shapes. However, the set of parameters allowing producing parts with highest geometrical and dimensional accuracy causes at the same time some microstructural issues, like great interlayer porosity or high number of non-processed powder particles embedded in the print structure.

Crop resistance and household resilience – The case of cassava and sweetpotato during super-typhoon Ompong in the Philippines

Extreme weather events can have devastating effects on agricultural production. As rural households in developing countries largely depend on agriculture, climatic shocks have the potential to undermine food security. In this paper, we explore how crop resistance contribute to household resilience in extreme weather events. As case study, we used cassava and sweetpotato, two root and tuber crops (RTCs), in the context of super-typhoon Ompong that wreaked havoc in the northern parts of the Philippines in 2018. Primary data were collected from 423 households who were affected by the super-typhoon. Methodologically, we employed a multivariate probit model to jointly estimate various household disaster responses, and applied propensity score matching techniques to control for potential endogeneity. The findings suggest that RTCs can contribute to households' resilience capacity due to their resistance to climatic shocks being underground crops. In addition, RTCs appear to be important in influencing the households’ responses to typhoon. Our findings suggest that RTC cultivation reduces the need to resort to negative coping strategies, such as using household savings and requesting assistance from neighbors and friends, and that higher consumption of sweetpotato is linked to longer spells of reduced mobility. Furthermore, in the case of super-typhoon Ompong, affected households exploited the short production cycle of sweetpotato and cassava and planted them in the typhoon aftermath, a strategy that helped to gain faster access to food. Based on these findings some policy recommendations are proposed.

Перспективные расы дрожжей для молодых игристых вин с мускатным ароматом

Introduction. In order to solve the growing demand for Muscat sparkling wines, some of the Muscat grapes used for the production of liqueur wines should be used as a raw material for sparkling wines. The technology of preparing young sparkling wines has a shorter production cycle. Science-based selection of the yeast race makes it possible to obtain young sparkling wines with a clear and bright Muscat aroma.
 Study objects and method. The research featured young sparkling wines from White Muscat grapes, produced using different yeasts races. The research involved both standard and modified methods of enochemical analysis.
 Results and discussion. The LALVIN QA-23 and Odesskiy Cherniy-SD-13 yeast races demonstrated a more active fermentation of Muscat white wort. The Sevastopolskaya 23 sample had in a slower fermentation, which promoted a greater accumulation of bound forms of carbon dioxide (16%). It contained the smallest amount of residual sugars (2 g/dm3) and thriable acids (6 g/dm3) and the largest amount of polyphenols (103 mg/dm3) and amine nitrogen (91 mg/dm3). Two samples accumulated a sufficient amount of free terpenes: 1.16 mg/dm3 for LALVIN QA-23 and 1.13 mg/dm3 for Sevastopolskaya 23. The degustation scores were quite high: LALVIN QA-23 received 9.03 points and Odesskiy Cherniy-SD-13 – 9.02 points, while Sevastopolskaya 23 scored 9.00 points. The LALVIN QA-23 sample proved to have the most pronounced varietal aroma, whereas the Odesskiy Cherniy-SD-13 sample possessed a more complex aromatic complex.
 Conclusion. The LALVIN QA-23 and Sevastopolskaya 23 yeast races were found suitable for bottle champagnization of young Muscat sparkling wines. They accumulated a sufficient amount of terpene alcohols. The samples had a clear Muscat aroma, harmonious taste, and good typical properties. The new method makes it possible to produce high quality sparkling wines in the harvest year.

A CONTROL SYSTEM FOR REMOTE MONITORING AND CONTROL OF THE TEMPERATURE IN CHICKEN EGGS HATCHING USING ARTIFICIAL INCUBATORS

According to OACD/FAO Agricultural Outlook, poultry meat remains the primary driver of growth in total meat production. Its short production cycle allows producers to respond quickly to market needs, as well as rapid improvements in genetics, animal health, feeding practices, breeding conditions and breeding environment. Hatching process needs to be done properly in order to maximize the number of healthy chickens hatched and to minimize their death rate. When using artificial egg incubation, it is important to monitor and control ambient conditions in incubators, to obtain ventilation and egg turning. Ambient conditions are expressed in terms of temperature and humidity, where maintaining and controlling the temperature inside the incubator is of the greatest importance. This paper deals with the description of a control system developed for remote monitoring and control of the temperature in chicken eggs hatching using artificial incubators. The system consists of heater in a form of an incandescent light bulb, temperature sensor, relay, microcontroller, and communication module. For temperature control, a PID (proportional-integral-derivative) controller is designed, which maintains the temperature at 37.8 °C. Temperature readings are available through the web browser and are accessible using wired Internet connection. Proposed system represents a simple, low-cost but very efficient solution which provides the necessary conditions for proper development of chickens while growing inside the egg.

Automated Production Scheduling for Artificial Teeth Manufacturing

In industrial artificial teeth manufacturing, nowadays a high level of automation is utilized to produce a large quantity of teeth in short production cycles. As a large variety of different product shapes and colors have to be processed on a single machine, the creation of efficient production schedules becomes a very challenging task. Due to the complexity of the problem and several cost minimization objectives that need to be considered, there usually is a large potential to improve the currently manually created schedules with automated solution methods. In this paper, we formally specify and solve a novel challenging real-life machine batch scheduling problem from the area of artificial teeth manufacturing. Additionally, we provide a collection of real-life benchmark instances that can be used to evaluate solution methods for the problem. To efficiently solve the problem, we propose an innovative construction heuristic and metaheuristic approach as well as an exact method using constraint programming. An extensive experimental evaluation shows that exact techniques can efficiently solve small scheduling scenarios and can provide optimal solutions for four instances. Furthermore, we show that the proposed metaheuristic approach is able to reach optimal results for small instances and can find high quality solutions also for large real-life benchmark instances.

Experimental Study on Lifting Technology of Hydraulic Driving Screw Pump

With the continuous development of oil fields, high gradient wells are increased year by year, highlight problem of high gradient wells is present in the low-volume oil wells. Low-volume wells in Dagang oil field land are mainly equipped with rod pump, with serious problem of partial grinding, short production cycle, and low pump efficiency. The the low-volume oil wells characterized by directional wells and horizontal wells in beach are mainly Equipped with ESP, and the trajectories of the wellbore are more complex than the land. The pump flow rate is less than that of the motor shell, the temperature rise of the unit, the motor burned, the cable breakdown and other problems are prominent in ESP lift, and production cycle is short. In view of the above problems, research on lift technology of hydraulic driving screw pump is carried out. the hollow screw is drived by the reverse circulation Power liquid, and the lifting efficiency is effectively improved. Through the test, The system can be adjusted in the range of 0.1-0.24L/s, to meet the production capacity of 10-20m3/d; the relatively constant ratio of power liquid and production Liquid is obtained in the system under different operating conditions, The results show that the whole structure can meet the requirements of large gradient wells or horizontal wells, achieving the production requirements of high gradient and low liquid oil wells.

Impacts of COVID-19 on Myanmar's chicken and egg sector, with implications for the sustainable development goals

CONTEXTChicken and eggs make important contributions to the food and nutrition security of low-income households in Myanmar, making it important to understand the impacts of COVID-19 on Myanmar's poultry sector. OBJECTIVEFirst, we evaluate the responsiveness and resilience of different chicken and egg farming systems in Myanmar to the shock of COVID-19. Second, we evaluate implications of the performance of the chicken and egg sector during COVID-19 for the Sustainable Development Goals. METHODSWe conducted six waves of telephone interviews from June to November 2020 with 269 chicken farms close to Yangon. We compared impacts in two types of production system - broilers and layers - using a survey of the same farms conducted in 2019 as a baseline. For each type of farm, we compared ‘integrated’ and ‘non-integrated’ farms, where integration involves combining production of chickens and fish. RESULTS AND CONCLUSIONSFirst, the COVID-19 pandemic severely impacted chicken and egg production. More than 30% of broiler farms and 10% of layer farms closed before June, 42% of long-term farmworkers were laid off, and indicators of business sentiment were much more pessimistic than in 2019. Second, the sector experienced a V-shaped recovery until September 2020 when a second wave of COVID-19 hit Myanmar. Third, the impacts of COVID-19 vary by production system. Broiler farms have a much shorter production cycle than layer farms and were able rapidly adjust operational status by closing or reopening, whereas very few layer farms reopened after closing. Fourth, integrated layer-fish farms proved more resilient to the shock of COVID-19 than layer farms, with 90% of layer-fish farms and 76% of layer farms remaining operational in November, but there was no difference in the performance of broiler-fish and broiler farms. Fifth, the slow supply response of layer farms has meant higher egg prices for consumers, likely affecting nutritional intakes and making it more difficult for Myanmar to achieve the second Sustainable Development Goal of ending hunger and malnutrition by 2030. SIGNIFICANCEThe results contribute to understanding of the challenges faced by chicken farms in Myanmar during the COVID-19 pandemic, and the effectiveness of their adaptive responses. Results have implications for other countries in Asia where integrated livestock-fish farms are common, and other developing countries where the poultry sector is expanding rapidly.

Design of Decontamination Device for Punching Sheet of Motor Rotor Core

In the stamping process of the iron core, the residual iron filings and oil stains on the surface are difficult to completely remove even through the cleaning process, and the cleanliness is difficult to reach the standard, which directly affects the product quality. Some manufacturers use manual auxiliary cleaning methods with high cost, low efficiency and uncontrolled product quality. Develop an automated decontamination device to improve product quality, shorten production cycle, and reduce labor costs. Thedecontamination device adopts a decontamination, absorption, antifouling, storagefouling multi-stage purification process to achieve the goal of meeting product cleanliness.

Improving Manufacturing Agility Through Optimal Production Scheduling System

The garment industry is a global industry that requires high agility in response to changing market demands that are quickly changing. Short product cycles with unpredictable demand often make the industry unable to meet consumer needs. In increasing the agility of production to deliver products to customers as fast as possible, the production scheduling system must be designed optimally. Recently algorithm hybridization is used because the combination of more than one algorithm is more optimal. Genetic Algorithm (GA) is a metaheuristic algorithm is applied in various production scheduling and its power can be improved by combining it with the Tabu Search (TS). The GA is the best metaheuristic algorithm to output the optimal scheduling with less execution time but has the disadvantage –easily trapped in local optimum (early convergence is faster). The TS algorithm works as a local search algorithm with a faster computation time than GA. This study aims to minimize the total time to complete the work (minimizing makespan) by combining TS into GA in conducting local searches to increase industrial agility. The results obtained are GA-TS hybridization can provide a more optimal solution for the production scheduling in the garment so that agility can increase.

Fertilization and Pre-Sowing Seed Soaking Affect Yield and Mineral Nutrients of Ten Microgreen Species

Microgreens, vegetable or herb seedlings consumed at a young growth stage, are considered to be a functional food with high concentrations of mineral nutrients and healthy beneficial bioactive compounds. The production of microgreens has been increasing in recent years. Vegetable growers are interested in growing microgreens as a new specialty crop due to their high market value, popularity, and short production cycles. However, there is a lack of research-based crop-specific recommendations for cultural practices including fertilization, pre-sowing seed treatments, and their effects on nutritional facts of microgreens. Ten microgreen species were evaluated for their shoot growth and mineral nutrient concentrations as affected by one-time post-emergence fertilization and pre-sowing seed soaking in two repeated experiments, from November 2018 to January 2019, in a greenhouse. The microgreen species varied in fresh and dry shoot weights, shoot height, visual rating, as well as macro- and micro-nutrient concentrations. Fertilization with a general-purpose soluble fertilizer (20-20-20 with micronutrients) at a rate of 100 mg·L−1 nitrogen (N) increased fresh shoot weight, and macro- and micro-nutrient concentrations in one or both experiments, with the exception of decreasing concentrations of calcium (Ca), magnesium (Mg), and manganese (Mn). Seed soaking consistently decreased fresh or dry shoot weight and nutrient concentrations when there was a significant effect.

Some modules of poultry production in Kaduna State, Nigeria

Poultry production plays a very important role in providing Nigerians with one of the cheapest sources of animal protein. In spite of this great nutritional contribution, some degree of discrepancies exist between its demand and supply vis a vis other economic expectations. This paper evaluates and compares the profitability of four layer production modules using input-output data from secondury sources (research reports and field experiences) and primary sources (2002/2003 input and output prices in Zaria). The modules covered by this paper are: started pullets (0-8 weeks), point of lay pullets (9-20 weeks), commercial egg production (21 - 72 weeks) and full cycle layer production (0)- 72 weeks). Fixed and variable costs were estimated for 500 birds and deducted from gross returns to give the net cash returns. The major investments in the started pullets and point of lay modules were the cost of pullets, accounting for about 61% and 50% of the total cost of production respectively. Feed constituted about 71% and 86% of the total cost of production in the commercial egg and full cycle layer production modules respectively. The analysis also indicate that sales of started and point of lay pullets accounted for over 90% of the gross income from started and point of lay modules while sales of eggs accounted for about 86% of the gross return from the other two modules. Net cash returns were positive for all the modules considered. The returns to Naira invested per year were 0.75, 0.09, 0.14 and 0.16, for started pullets, point of lay, egg production and full cycle layer modules respectively. It is cvident from these results that modules with shorter production cycle tends to generate higher returns to investment, as more batches are turnout per year depending on the length of productiun cycle.

O processo de compras: um estudo teórico de sua relação com o ciclo produtivo da indústria do vestuário

A área de compras tem importância estratégica para os negócios dos diversos setores, inclusive para as indústrias de vestuário, que exige um olhar sob suas especificidades. Este trabalho tem como objetivo analisar como o processo de compras está inserido no ciclo produtivo da indústria do vestuário identificando as relações existentes com outros processos. O delineamento utilizado foi uma pesquisa exploratória de caráter qualitativo, a partir da busca em publicações existentes sobre o tema. Descobriu-se que há lacunas sobre o processo de compras em publicações da área de moda, que o setor de compras atua juntamente com outros setores com a finalidade de suprir o curto ciclo produtivo, que esse setor é responsável por criar informações importantes para o processo produtivo. A partir disso o estudo apresenta um esquema que contempla a inserção do processo de compras no ciclo produtivo da indústria do vestuário. Esse resultado é importante por destacar a importância da área de compras para o setor de vestuário e consequentemente beneficia as discussões em torno da cadeia de suprimentos.

Load-dependent path planning method for 3D printing of continuous fiber reinforced plastics

3D printing, to print continuous fiber reinforced plastics (CFRPs) has advantages of manufacturing complex shape and short production cycle. Due to anisotropic mechanical properties of continuous fibers, the paving direction of the fibers determines the mechanical strengths of the printed CFRPs. In this paper, a novel load-dependent path planning (LPP) method has been proposed to generate printing path for CFRPs, which exactly follows the load transmission path of the parts and could provide higher mechanical properties. A topology optimization method is applied to simplify the original disordered load distribution. In the developed Stress Vector Tracing (SVT) algorithm, the printing paths are generated along the load transmission path with the variable spacing of adjacent paths. The LPP method has been compared with the state-of-the-art printing path planning method for continuous fibers and shown better load-bearing and printability.

Construction and optimization of p-coumaric acid-producing Saccharomyces cerevisiae

p-Coumaric acid is an important precursor of various natural compounds, such as flavonoids and stilbenes. It has been widely used in biomedicine, food, nutrition and health care industries. Compared with traditional plant extracts and chemical synthesis, microbial synthesis of natural compounds such as p-coumaric acid has attracted wide attention due to its short production cycle and high conversion efficiency. Here a p-coumaric acid-producing Saccharomyces cerevisiae platform strain was developed. First, the tyrosine synthesis competition pathway genes ARO10 and PDC5 were knocked out, and ARO4(K229L) and ARO7(G141S) were mutated to release negative feedback inhibition from tyrosine. The tyrosine ammonia-lyase coding gene TAL from Flavobacterium johnsoniaeu was then integrated into genome and obtained C001 with yield of p-coumaric acid 296.73 mg/L. To further increase the accumulation of p-coumaric acid precursors, 8 genes encoding amino acids and carbohydrate transporters were knocked out and the gluconeogenesis pathway was enhanced. The results showed that GAL2 knockout and overexpression of EcppsA increased the yield of p-coumaric acid to 475.11 mg/L. Finally, the effect of FjTAL anchoring to yeast vacuoles on product accumulation was analyzed, and the highest titer of p-coumaric acid of 593.04 mg/L was obtained after intracellular vacuolar localization of FjTAL. It provided an efficient p-coumaric acid-producing platform strain for the subsequent synthesis of flavonoids and stilbene compounds by enhancing the supply of precursors, blocking the competitive bypass pathway, and using the strategy of subcellular localization.