Coordination of Multiechelon Supply Chains Using the Guaranteed Service Framework

Problem definition: We use the guaranteed service (GS) framework to investigate how to coordinate a multiechelon supply chain when two self-interested parties control different parts of the supply chain. For purposes of supply chain planning, we assume that each stage in a supply chain operates with a local base-stock policy and can provide guaranteed service to its customers, as long as the customer demand falls within certain bounds. Academic/practical relevance: The GS framework for supply chain inventory optimization has been deployed successfully in multiple industrial contexts with centralized control. In this paper, we show how to apply this framework to achieve coordination in a decentralized setting in which two parties control different parts of the supply chain. Methodology: The primary methodology is the analysis of a multiechelon supply chain under the assumptions of the GS model. Results: We find that the GS framework is naturally well suited for this decentralized decision making, and we propose a specific contract structure that facilitates such relationships. This contract is incentive compatible and has several other desirable properties. Under assumptions of complete and incomplete information, a reasonable negotiation process should lead the parties to contract terms that coordinate the supply chain. The contract is simpler than contracts proposed for coordination in the stochastic service (SS) framework. We also highlight the role of markup on the holding costs and some of the difficulties that this might cause in coordinating a decentralized supply chain. Managerial implications: The value from the paper is to show that a simple contract coordinates the chain when both parties plan with a GS model and framework; hence, we provide more evidence for the utility of this model. Furthermore, the simple coordinating contract matches reasonably well with practice; we observe that the most common contract terms include a per-unit wholesale price (possibly with a minimum order quantity and/or quantity discounts), along with a service time from order placement until delivery or until ready to ship. We also observe that firms need to pay a higher price if they want better service. What may differ from practice is the contract provision of a demand bound; our contract specifies that the supplier will provide GS as long as the buyer’s order are within the agreed on demand bound. This provision is essential so that each party can apply the GS framework for planning their supply chain. Of course, contracts have many other provisions for handling exceptions. Nevertheless, our research provides some validation for the GS model and the contracting practices we observe in practice.

ASSESSMENT OF THE ECONOMIC EFFECT OF ENERGY STORAGE SYSTEM PROVIDING THE BAL-ANCING SERVICES IN THE IPS OF UKRAINE

The article presents a simulation model for estimating the economic effect of the energy storage systems providing the balancing electricity to the Transmission System Operator in the balancing market segment. The model simulates the serial charge and discharge of storage (i.e., sequential provision of unloading and loading services). Peculiarities of considering the cost of purchase, installation, and maintenance of energy storage systems with reduction both to the guaranteed service life and the guaranteed resource of charge/discharge cycles are given. An example of the application of the simulation model for estimating the economic effect and payback period of energy storage systems in the provision of electricity balancing services in the balancing market segment is shown. Ref. 15.

Method of arc activation of the base at increasing the distance plasma spraying

Purpose. To increase the efficiency of the plasma coating by developing a method of ion-arc activation of the base using an activating electrode, which leads to an increase in the adhesion strength of the coating due to the sputtering of surface oxides of the base. Research methods. Experimental and computational, mechanical tests, optical microscopy. The development of the method of ion-arc activation of the part base with an increase in the distance of coating deposition consists in application of an activating electrode located at the surface of the base to create an additional activating arc. The influence of the activating arc on bases for creating an additional activating arc. The influence of the activating arc on the adhesion strength of the coating is determined. The estimation of the current density of the activating arc for the sputtering of surface base oxides is carried out. Results. A method of arc activation of the base surface with an increase in the coating distance is found. It is shown that application of an activating arc of reverse polarity that burns between the additional electrode and the base leads to ion bombardment of the surface by sputtering surface oxides and the creation of microcraters on the base surface. As a result, the bond strength is doubled compared to the bond strength obtained without the use of ion-arc activation of the base. The calculations of the rate of cathodic sputtering of the surface oxides of the base are carried out and the minimum activation current density of the base is determined, which leads to the complete sputtering of a layer of oxides of a given thickness. Scientific novelty. It has been determined that, despite the rapid oxidation of the base under atmospheric conditions, application of the method of ion-arc cleaning of the surface during coating leads to a significant increase in the adhesion strength of the coating to the base. Practical value. The obtained results of increasing the adhesion strength rise the efficiency, the guaranteed service life of the plasma coating on the parts of machines and mechanisms

About the repair of closed tubular drainage of the land reclamation section of an agricultural field in the Pskov region

On the lands of the Trigorskoye farm, in September 2020, an offsite seminar was held by the section of reclamation of agricultural lands of the Scientific Council of the Agrophysical Research Institute. The seminar participants included more than 30 specialists in the field of agricultural reclamation. The work on cleaning the tubular collector from the flow regulator well with the Poseidon installation with a jet flushing nozzle was demonstrated. The results of the removal of sludge from the tubular collector were verified by the method of excavation and extraction of pipes from the drainage line. Experts of the Agrophysical Research Institute, using an unmanned aerial vehicle, surveyed a section of the drainage reclamation system in order to determine the locations of faults in the closed tubular drainage. The results of the studies obtained will be used by the design and operating organizations of the Pskov region in the development of new technologies for restoring the operation of the drainage pipe drainage with its expired guaranteed service life.

Impact of Processed Food (Canteen and Oil Wastes) on the Development of Black Soldier Fly (Hermetia illucens) Larvae and Their Gut Microbiome Functions

Canteens represent an essential food supply hub for educational institutions, companies, and business parks. Many people in these locations rely on a guaranteed service with consistent quality. It is an ongoing challenge to satisfy the demand for sufficient serving numbers, portion sizes, and menu variations to cover food intolerances and different palates of customers. However, overestimating this demand or fluctuating quality of dishes leads to an inevitable loss of unconsumed food due to leftovers. In this study, the food waste fraction of canteen leftovers was identified as an optimal diet for black soldier fly (Hermetia illucens) larvae based on 50% higher consumption and 15% higher waste reduction indices compared with control chicken feed diet. Although the digestibility of food waste was nearly twice as high, the conversion efficiency of ingested and digested chicken feed remains unparalleled (17.9 ± 0.6 and 37.5 ± 0.9 in CFD and 7.9 ± 0.9 and 9.6 ± 1.0 in FWD, respectively). The oil separator waste fraction, however, inhibited biomass gain by at least 85% and ultimately led to a larval mortality of up to 96%. In addition to monitoring larval development, we characterized physicochemical properties of pre- and post-process food waste substrates. High-throughput amplicon sequencing identified Firmicutes, Proteobacteria, and Bacteroidota as the most abundant phyla, and Morganella, Acinetobacter, and certain Lactobacillales species were identified as indicator species. By using metagenome imputation, we additionally gained insights into the functional spectrum of gut microbial communities. We anticipate that the results will contribute to the development of decentralized waste-management sites that make use of larvae to process food waste as it has become common practice for biogas plants.

Physico-mechanical and technological characteristics of composite materials based on mixtures of secondary thermoplastics

The physico-mechanical and technological characteristics of mixed waste of thermoplastic polymers, including that from the recyclable electronic and electrical equipment based on ABS plastic, were investigated. Target modifying additives were introduced into the composite system to improve the compatibility of polymer components of mixtures and the stable rheological properties of composition during processing. It is established that the secondary polymers behavior in their mixtures is caused by combination of their rheological characteristics and other parameters of mutual compatibility, that has significant impact on phase composition and microphases mutual order. Dispersed additives make a significant contribution to these processes, affecting the structuring of the associated polymer microvolumes. Target regulation of the rheological properties of components will ensure the achievement of acceptable and reproducible physico-mechanical characteristics and technological parameters of process, which will create prerequisites for the production of competitive products with a high guaranteed service life without use of scarce raw materials. Composite materials have been developed that are adapted to stable processing by extrusion, injection molding, and formation molding into technical products with acceptable performance characteristics.