Optimal Retail Pricing for Demand Response of HVAC Systems in Commercial Buildings Considering Distribution Network Voltages

Retail pricing can be well deployed with support of distribution companies (DISCOs) to promote demand response (DR) programs using heating, ventilating, and airconditioning (HVAC) systems as thermal energy storage resources. This paper proposes a retail pricing strategy to assist a DISCO and end-users in achieving optimal price-based DR for HVAC systems while considering operational aspects of distribution network. The pricing strategy is developed using a bi-level decision model. In the upper level, the DISCO optimizes the retail price to maximize its profit. In the lower level, the end-users schedule HVAC loads to minimize their electricity bills. The nonlinear thermal response model of an experimental building room is integrated with a data-driven model of an HVAC system and incorporated into the pricing strategy using piece-wise linear approximation. The proposed strategy also employs time-of-use rates as retail price caps, leading to low-level price volatility. Case studies are presented for various ranges of bus voltage deviation and penetration levels of HVAC systems. The results demonstrate that the proposed strategy is effective for determining the optimal balancing point between the DISCO's profit and end-users' electricity bills while enabling the DISCO to reliably regulate the network voltages via the price-sensitive HVAC units.11Nsciescopu

Retail electricity pricing via online-learning of data-driven demand response of HVAC systems

This paper proposes an online-learning-based strategy for a distribution system operator (DSO) to determine optimal retail prices, considering the optimal operations of heating, ventilation, and air-conditioning (HVAC) systems in commercial buildings. An artificial neural network (ANN) is trained online with building energy data and represented using an explicit set of linear and nonlinear equations. An optimization problem for price-based demand response (DR) is then formulated using the explicit ANN model and repeatedly solved, producing data on optimal HVAC load schedules for various profiles of electricity prices and building environments. Another ANN is then trained online to predict directly the optimal load schedules, which is referred to as meta-prediction (MP). By replacing the DR optimization problem with the MP-enabled ANN, optimal retail electricity pricing can be achieved using a single-level decision-making structure. Consequently, the pricing optimization problem becomes simplified, enabling easier implementation and increased scalability for HVAC systems in a large distribution grid. In case studies, the proposed single-level pricing strategy is verified to successfully reflect the game-theoretic relations between the DSO and building operators, such that they effectively achieve their own objectives via the operational flexibility of the HVAC systems, while ensuring grid voltage stability and occupants' thermal comfort.11Nsciescopu

Salvage therapy using self-expandable metal stents for recalcitrant anastomotic strictures after living-donor liver transplantation

Background: Recently, there has been an increase in clinical success rates using nonsurgical methods to resolve anastomotic biliary strictures (ABSs) that develop after liver transplantation (LT). However, some strictures are particularly refractory and cannot be completely resolved by an endoscopic or percutaneous procedure. Consequently, the aim of this study was to examine the feasibility and efficacy of using a newly designed fully covered self-expandable metal stent (FCSEMS) to resolve refractory ABS. Methods: A total of 35 patients with an ABS that developed after LT, but could not be resolved by an endoscopic or percutaneous procedure, were included in this study. FCSEMSs were positioned endoscopically and removed after 2–3 months. After stent removal, the patients were followed to assess complications, including re-stenosis. Results: The mean period from LT to stricture was 13.7 months, and the mean duration of the stricture was 31.8 months. The type and mean number of procedures previously attempted were endoscopic retrograde cholangiopancreatography (ERCP) (9.1 ± 5.1) in 19 patients and percutaneous transhepatic biliary drainage (9.2 ± 4.8) in 16 patients. All patients had successful FCSEMS insertions and removals; the mean stent indwelling time was 3.2 months. The mean follow-up period was 18.7 months (range: 6.4–37.8 months). Stricture recurrence was observed in 6 of 29 patients (recurrence rate: 20.7%). The anastomotic stricture resolved with the FCSEMS insertion in 29 of 35 patients (clinical success rate: 82.9%). Conclusions: The newly designed FCSEMS is a potentially feasible and effective treatment for anastomotic strictures that develop after LT but are not amenable to treatment by conventional procedures

An origin identification model for labeling of shiitake (Lentinula edodes)

Abstract With the increasing globalization of the food trade across countries and continents, reliable identification of the geographical origin of products is critical. In this study, we describe the limitations of the current origin labeling system for non-soil-based agricultural products and suggest alternative strategies for the identification of the geographical origin of such products. An origin identification model based on stable isotope ratio analysis combined with discriminant analysis is used to evaluate the similarities and dissimilarities between domestic and foreign shiitake mushrooms, including Chinese inoculated sawdust blocks and Chinese origin. The results show a classification sensitivity of 92.0%, classification specificity of 91.5%, and overall accuracy of 93.5%. In particular, δ15N was the most important isotope marker for the identification of the origin of shiitake mushrooms. Hence, the current origin labeling system for mushroom species has to be revised to establish fair trade and avoid improper origin labeling in the global shiitake market

Assessment of Benefits and Risk of Genetically Modified Plants and Products: Current Controversies and Perspective

Genetic transformation has emerged as an important tool for the genetic improvement of valuable plants by incorporating new genes with desirable traits. These strategies are useful especially in crops to increase yields, disease resistance, tolerance to environmental stress (cold, heat, drought, salinity, herbicides, and insects) and increase biomass and medicinal values of plants. The production of healthy plants with more desirable products and yields can contribute to sustainable development goals. The introduction of genetically modified food into the market has raised potential risks. A proper assessment of their impact on the environment and biosafety is an important step before their commercialization. In this paper, we summarize and discuss the risks and benefits of genetically modified plants and products, human health hazards by genetically transformed plants, environmental effects, Biosafety regulations of GMO foods and products, and improvement of medicinal values of plants by the genetic transformation process. The mechanisms of action of those products, their sources, and their applications to the healthcare challenges are presented. The present studies pointed out the existence of several controversies in the use of GMOs, mainly related to the human health, nutritions, environmental issues. Willingness to accept genetically modified (GM) products and the adoption of biosafety regulations varies from country to country. Knowledge about the gene engineering technology, debate between the government agencies, scientist, environmentalist and related NGOs on the GM products are the major factors for low adoptions of biosafety regulation. Therefore, the genetic transformation will help in the advancement of plant species in the future; however, more research and detailed studies are required

BRCA 1/2 Germline Mutation Predicts the Treatment Response of FOLFIRINOX with Pancreatic Ductal Adenocarcinoma in Korean Patients

We evaluated the proportion of BRCA 1/2 germline mutations in Korean patients with sporadic pancreatic ductal adenocarcinoma (PDAC) and its effect on the chemotherapeutic response of FOLFIRINOX. This retrospective study included patients who were treated at two tertiary hospitals between 2012 and 2020, were pathologically confirmed to have PDAC, and had undergone targeted next-generation sequencing-based germline genetic testing. Sixty-six patients were included in the study (24 men; median age 57.5 years). In the germline test, BRCA 1/2 pathogenic mutations were found in nine patients (9/66, 13%, BRCA 1, n = 3; BRCA 2, n = 5; and BRCA 1/2, n = 1). There was no significant difference in the baseline characteristics according to BRCA mutation positivity. Among patients who underwent FOLFIRINOX chemotherapy, patients with a BRCA 1/2 mutation showed a higher overall response rate than those without a BRCA 1/2 mutation (71.4% vs. 13.9%, p = 0.004). Patients with a germline BRCA 1/2 mutation showed longer progression-free survival than those without a BRCA 1/2 mutation, without a significant time difference (18 months vs. 10 months, p = 0.297). Patients with a BRCA 1/2 mutation in the germline blood test had a higher response rate to FOLFIRINOX chemotherapy in PDAC. The high proportion of BRCA 1/2 germline mutations and response rate supports the need for germline testing in order to predict better treatment response