More Physical Activity after Concussion Is Associated with Faster Return to Play among Adolescents

Concussion management has evolved to de-emphasize rest in favor of early introduction of post-injury physical activity. However, the optimal quantity, frequency and intensity of physical activity are unclear. Our objective was to examine the association between objective physical activity metrics and clinical recovery after concussion. We prospectively enrolled a cohort of 32 youth athletes with concussion, evaluated within 14 days of injury and after return-to-play (RTP) clearance. For two weeks after enrollment, we quantified steps/day and exercise frequency, duration, and intensity via wrist-worn actigraphy. We grouped participants by RTP clearance timing (<28 days vs. ≥28 days). Seventeen (53%) participants required ≥28 days post-concussion for RTP clearance. Groups were similar in age (14.9 ± 1.9 vs. 15.4 ± 1.5 years; p = 0.38), proportion of females (47% vs. 40%; p = 0.69), and concussion history (59% vs. 47%; p = 0.49). During the study period, the RTP ≥ 28 days group took fewer steps/day (8158 ± 651 vs. 11,147 ± 4013; p = 0.02), exercised fewer days/week (2.9 ± 2.4 vs. 5.0 ± 1.9 days/week; p = 0.01), and exercised fewer total minutes/week (117 ± 122 vs. 261 ± 219 min/week; p = 0.03). Furthermore, we observed ≥10,251 average steps/day, ≥4 exercise sessions/week, and exercising ≥134 total minutes/week were optimal cutpoints to distinguish between groups. These findings support the benefit of physical activity during concussion recovery.

Extrusion Based 3D Printing of Sustainable Biocomposites from Biocarbon and Poly(trimethylene terephthalate)

Three-dimensional (3D) printing manufactures intricate computer aided designs without time and resource spent for mold creation. The rapid growth of this industry has led to its extensive use in the automotive, biomedical, and electrical industries. In this work, biobased poly(trimethylene terephthalate) (PTT) blends were combined with pyrolyzed biomass to create sustainable and novel printing materials. The Miscanthus biocarbon (BC), generated from pyrolysis at 650 °C, was combined with an optimized PTT blend at 5 and 10 wt % to generate filaments for extrusion 3D printing. Samples were printed and analyzed according to their thermal, mechanical, and morphological properties. Although there were no significant differences seen in the mechanical properties between the two BC composites, the optimal quantity of BC was 5 wt % based upon dimensional stability, ease of printing, and surface finish. These printable materials show great promise for implementation into customizable, non-structural components in the electrical and automotive industries.

Penentuan Kuantitas Produksi Kue Brownies yang Optimal pada Model Persediaan Periode Tunggal

Inventory is an important part of a manufacturing company, both before the production process begins, during the production process or after the production process is complete. Inventory control in a company must be carried out as optimally as possible. Shortage or excess of inventory will cause losses for the company. Holding costs will be large if there is excess inventory. With the availability of inventory management, it can anticipate a surge in demand from consumers. Inventory management is also used to optimize inventory as possible to reduce inventory costs. In this thesis, analyze the optimal quantity of brownie cake production using a single period model. In this model, it must determine the level of inventory, the holding cost of inventory, and the cost of shortage of inventory. Once determined, it can be seen from the optimal brownies cake production results. Based on the results of the data analysis of the optimal quantity of brownie cake production, it can be seen that the optimal of 8 packages or 200 pcs with an expected total cost of Rp. 12.825.540. Abstrak. Persediaan merupakan bagian yang penting dalam suatu perusahaan manufaktur, baik sebelum proses produksi dimulai, saat proses produksi berlangsung maupun setelah proses produksi selesai. Pengendalian persediaan dalam suatu perusahaan harus dilakukan seoptimal mungkin. Kekurangan maupun kelebihan persediaan akan dapat menimbulkan kerugian bagi perusahaan. Biaya penyimpanan akan menjadi besar bila terjadi kelebihan persediaan. Dengan adanya manajemen persediaan dapat mengantisipasi lonjakan permintaan dari konsumen. Manajemen persedian juga berguna untuk mengoptimalkan persediaan seoptimal mungkin guna mengurangi biaya persediaan. Pada skripsi ini, di lakukan analisis penentuan kuantitas produksi kue brownies yang optimal dengan menggunakan model periode tunggal. Pada model ini harus menentukan level inventory, biaya simpan, dan biaya kekurangan persediaan. setelah ditentukan maka dapat dilihat hasil produksi kue brownies yang optimal. Berdasarkan hasil analisis data kuantitas produksi kue brownies yang optimal sebanyak 8 pack atau 200 pcs dengan ekspektasi ongkos total Rp. Rp. 12.825.540.

THEORETICAL ASPECTS OF THE DEVELOPMENT OF NEW TYPES OF CONFECTIONERY PRODUCTS OF INCREASED NUTRITIONAL VALUE AND DIRECTED EFFICIENCY

The article presents the main results of fundamental research carried out by specialists of the group for the confectionery industry of the technology confectionery and oil and fat products department in 2008–2020. The chemical composition and technological properties of soluble fibers — inulin and oligofructose, as well as the source of inulin — Jerusalem artichoke, have been studied, their optimal dosages in the manufacture of zephyr have been determined, allowing to achieve technological effects and enrich the finished product with food fibers. Studied the composition of the linen cake and its influence on the quality of biscuits. The optimal dosages of linen cake have been established to increase the nutritional and biological value of the biscuits. The possibility of using durum wheat flour in the manufacture of biscuits has been studied. Influence of proteolytic enzyme, sugar and fat on protein proteolysis in confectionary dough for production of soluble biscuits is studied. It is defined that sugar and fat reduce speed of protein proteolysis, at that sugar has more inactivate ability. Optimal quantity of proteolytic enzyme is 0,15 % to mass of wheat flour. The rheological properties of syrups based on sweeteners for muesli bars have been investigated. Established the ratio of maltitol and maltitol syrup in the recipe for muesli bars for diabetic nutrition.

Inventory routing of industrial gases with stochastic demand

This report proposes a methodology to solve the inventory routing problem of industrial gases with stochastic demand. The gas tanker distributes gases from a depot to several dispersed customers in a route, and each customer has stochastic demand modeled by a Brownian motion. The proposed model determines the optimal quantity required to refill each customer by minimizing the cost associated with earliness, which increases number of visits per year, and lateness, which increases probability of stockout. Overall, the proposed model minimizes the total system cost, helps find the optimal tanker capacity for a given route, and improves supplier and customers' relationship. Numerical examples and sensitivity analysis are given to illustrate the proposed model.

Inventory routing of industrial gases with stochastic demand

This report proposes a methodology to solve the inventory routing problem of industrial gases with stochastic demand. The gas tanker distributes gases from a depot to several dispersed customers in a route, and each customer has stochastic demand modeled by a Brownian motion. The proposed model determines the optimal quantity required to refill each customer by minimizing the cost associated with earliness, which increases number of visits per year, and lateness, which increases probability of stockout. Overall, the proposed model minimizes the total system cost, helps find the optimal tanker capacity for a given route, and improves supplier and customers' relationship. Numerical examples and sensitivity analysis are given to illustrate the proposed model.

APPLICATION OF PERIODIC REVIEW INVENTORIES MODEL IN A TYPICAL MEXICAN FOOD COMPANY

The Mexican family companies must face the challenges of market volatility with greater recurrence, forcing them to use effective tools and models for the proper management of their organizations and inherent activities, such as inventory management. Therefore, this research was carried out at “Moles Santa Monica”, a typical food company located in the city of Puebla, Mexico. This enterprise has reflected a high variability in the administration of its inventories, with a Coefficient of Variation (CV) greater than 0.2 in most of their portfolio products. In this way, the objective of this study was to propose an inventory management model that might reduce the shortages and overstock, and also; improves its performance and profitability when it is managed. The applied methods were Pareto and ABC model to choose correctly the best seller company products. The inventory management model chosen was the periodic review (R, S) as well, for being the most effective and the one that best suited the circumstances of the company in question. Three of the portfolio products were studied (MPP10, MPC10 and COP10) due to they are the most representative in incomes and valuables for the company managers. The results allowed us to propose the review periodic model (R), the optimal quantity of units to produce (Q), the safety stock (Ss) and the maximum inventory (S) for each product. We conclude that this model will help the company to face the uncertainty of the demand. Finally, we include limitations and future studies.

The Nature of Money in a Convertible Currency World

In a world where the means of exchange is convertible into the numeraire consumption good at a fixed rate, no one wants to hold money over time – and due to convertibility there is no means by which the Friedman rule can generate deflation. This is the environment we study in this paper in order to demonstrate that there is still a way to reach the first-best: institutionalize the naked shorting of the unit of account, or in other words establish a banking system. To motivate the benefits of a banking system, the environment has real productivity shocks that are constantly changing the optimal level of economic activity, so the optimal quantity of money is inherently stochastic. Efficiency in such an environment requires the capacity to expand the money supply on an “as needed” basis. We show how a debt-based payments system that relies on banks to certify the individual debtors’ IOUs addresses the monetary problem. This model explains (i) central bank monetary policy as a means of stabilizing the banking system and (ii) usury laws as means of promoting equilibria that favor non-banks over those that favor banks. Furthermore, by modeling a commercial bank-based monetary system as an efficient solution to a payments problem this paper develops a theoretic framework that may be used to evaluate central bank digital currency proposals.

COVID-19 SOCIAL DISTANCING AND PROFIT MAXIMIZATION INVENTORY MODEL WITH OVERAGE

Goal: This research work aims in presenting the impacts of social distancing on the societal domain in particularly with the special focus on inventory management, the accelerating fuel of the production sectors. A profit maximization inventory model comprises of overage management, waste disposal and product propagation is proposed. Design / Methodology / Approach: A mathematical model with the objective of profit maximization and overage management is developed to cater the needs of the production sectors at times of pandemic situation. Results: This model yields the optimal quantity (Qα) that maximizes the expected aggregate profit per unit of time. Limitations of the investigation: This research is of exploratory kind and the lack of similar research in the literature locks the opportunity of comparison, also the proposed model is a more generalized in nature. Practical implications: The proposed maximization model will certainly assist the decision makers to handle the situations of overage caused by pandemic social distancing. Originality/Value: The combination of profit maximization, overage management in the context of COVID 19 social distancing is modelled to benefit the production sectors and this is the novel approach of this article.