Dynamic Range of Frontoparietal Functional Modulation is Associated with Working Memory Capacity Limitations in Older Adults

Older adults tend to over-activate regions throughout frontoparietal cortices and exhibit a reduced range of functional modulation during WM task performance compared to younger adults. While recent evidence suggests that reduced functional modulation is associated with poorer task performance, it remains unclear whether reduced range of modulation is indicative of general WM capacity-limitations. In the current study, we examined whether the range of functional modulation observed over multiple levels of WM task difficulty (N-Back) predicts in-scanner task performance and out-of-scanner psychometric estimates of WM capacity. Within our sample (60–77 years of age), age was negatively associated with frontoparietal modulation range. Individuals with greater modulation range exhibited more accurate N-Back performance. In addition, despite a lack of significant relationships between N-Back and complex span task performance, range of frontoparietal modulation during the N-Back significantly predicted domain-general estimates of WM capacity. Consistent with previous cross-sectional findings, older individuals with less modulation range exhibited greater activation at the lowest level of task difficulty but less activation at the highest levels of task difficulty. Our results are largely consistent with existing theories of neurocognitive aging (e.g. CRUNCH) but focus attention on dynamic range of functional modulation as a novel marker of WM capacity-limitations in older adults

A cryogenic scan mechanism for use in Fourier transform spectrometers

This paper describes the requirements, design, assembly and testing of the linear Scan Mechanism (SM) of the Composite Infrared Spectrometer (CIRS) Instrument. The mechanism consists of an over constrained flexible structure, an innovative moving magnet actuator, passive eddy current dampers, a Differential Eddy Current (DEC) sensor, Optical Limit Sensors (OLS), and a launch lock. Although all the components of the mechanism are discussed, the flexible structure and the magnetic components are the primary focus. Several problems encountered and solutions implemented during the development of the scan mechanism are also described

Numerical Simulation of Arctic Offshore Structures Interacting with Level Ice and Nonlinear Time-Domain Simulations of Arctic Spar

One of the greatest challenges of developing the arctic regions is the harsh environmental conditions caused by the presence of ice. When offshore structures interact with ice, significant structural motion is induced by the ice load, which influences the overall structural robustness. In this study, three different numerical tools are developed to investigate the ice-structure interaction using three scenarios. First, the fixed-type monopile offshore wind turbine in level ice is studied. Because the crushing is the dominant failure mode of level ice against a cylindrical structure, a mechanical ice-crushing model is developed to estimate the ice force on the structure in time domain. The model is further implemented into the wind turbine analysis software, FAST, developed by National Renewable Energy Laboratory (NREL). Second, the floating offshore platform, Artic Spar, in level ice is investigated by employing an analytical method. Artic Spar is characterized by the inverted cone-shaped hull near the waterline so that level ice can fail when bending. The fully coupled floater-riser-mooring dynamic analysis program, CHARM3D, is extended by implementing the analytical ice-bending model. Third, the numerical software for the interaction between level ice and an arbitrary-shaped floating offshore structure is developed by coupling two software programs, LIGGGHTS and CHARM3D. Based on the discrete element method, level ice is modelled as an assembly of multiple spherical particles, and the bonding parallel method is employed to consider the interaction force among the bonded particles. Throughout the newly developed numerical simulation tools, the ice load on different offshore structures is numerically estimated, and the corresponding structural performances are systematically investigated. In addition to these three ice-structure interactions, the nonlinear behavior or Arctic Spar is investigated in time domain. To capture the nonlinearity of platform motions, a nonlinear time-domain simulation tool considering the nonlinear hydro-restoring coefficient and nonlinear Froude-Krylov force is developed by extending CHARM3D with a body-nonlinear method. The heave-to-pitch and heave-to-heave Mathieu instabilities of Arctic Spar are also investigated in both regular and irregular waves

A study of the changing complexion of academic governance in New Jersey community colleges

The purpose of this study was to determine the forces of change that will affect community colleges in New Jersey and to capture the attitudes of stakeholders towards the impact of these forces as they relate to the future of the structure of academic governance. The target population of this study was community college administrators and faculty in five community colleges in southern New Jersey (n=90). The study included a random sample of administrators and faculty members, with an overall response rate of 43.5%. In addition to the survey, 12 stakeholders were randomly chosen to participate in interviews, representing a sample of convenience. The survey data were analyzed using the Statistical Package for Social Sciences (SPSS) version 12.0, which calculated frequencies, percentages, means, and standard deviations. Interview data were analyzed by categorizing the comments, predictions, and opinions made by the faculty members and administrators. The research has found that community colleges in New Jersey face many changes that will challenge decision-making processes as autonomy from state control continues to expand, requirements for broader sources of funding for growth and expansion of technologies continue to increase, and internal management continues to migrate to a shared governance structure

Effect of Dilute Acid Pretreatment of Vegetable Waste on Sugar Production and Inhibitor Formation

Vegetable waste is an organic waste with high cellulose and hemicellulose and low lignin content. The cellulose and hemicellulose chains can be broken down by pretreatment using sulfuric acid to obtain reducing sugar. To avoid the formation of degradation products that have the potential as inhibitor compounds, the temperature of the pretreatment operation was carried out at 121 and 125 for 60 minutes with sulfuric acid concentrations varying from 0.5% to 1.5% (v/v). The solid and liquid ratio (S/L) was 5% (w/v). From the experiments, the highest total reducing sugars of 7.068 g/L was obtained by pretreatment conditions at 121 for 60 minutes with a sulfuric acid concentration of 1% (v/v). Meanwhile, the lowest total reducing sugar of 2.764 g/L was produced during the pretreatment operating conditions at 125 for 60 minutes with a sulfuric acid concentration of 1% (v/v). Under the present experimental condition, it was found that only a low level of degradation product was formed, which ensures excellent performance of bacterial growth in the subsequent fermentation process

Pra Desain Pabrik Margarin dari Kacang Tanah dengan Proses Hidrogenasi BErkapasitas 3856 Ton/Tahun

Dalam penelitian ini telah dilakukan perancangan pabrik margarin dari kacang tanah dengan proses hidrogenasi berkapasitas produk sebesar 3.856 ton/tahun, waktu operasi 24 jam dan 330 hari/tahun. Tujuan perancangan pabrik margarin ini adalah untuk memenuhi 5% dari total kebutuhan margarin dalam negeri. Pabrik margarin ini direncanakan akan didirikan di Kabupaten Tuban, Jawa Timur. Alasan pemilihan tempat ini adalah karena potensi bahan baku yang tersedia mampu memenuhi kebutuhan ketersediaan bahan baku kacang tanah untuk pabrik margarin, dekat dengan pasar, dan sarana-prasarana yg mendukung. Pembuatan margarin dari minyak kacang tanah ini dipilih proses hidrogenasi. Proses dalam pabrik ini terdiri dari 4 tahap utama yaitu tahap persiapan bahan baku, tahap pressing, pemurnian, hidrogenasi, dan emulsifikasi. Sumber dana investasi berasal dari modal sendiri sebesar 70% biaya investasi dan modal pinjaman sebesar 30% biaya investasi dengan bunga sebesar 10,25% per tahun. Dari analisa perhitungan ekonomi didapat hasil investasi Rp 139.24.579.000,00, dengan IRR 14,4 %, POT 6 tahun dan BEP 62,05 %

Study of UV-B Mutation Effect on pH Resistance and Lipid Production of Microalgae Botryococcus braunii

Microalgae Botryococcus braunii is a potential biodiesel producer as an alternative for fossil fuels due to its high lipid content. UV-B mutations were carried out to see the effect in microalgae growth at various pHs (3-8). Reduction of nitrogen levels was carried out to see the effect on the growth and lipid production of microalgae. UV-B mutation increased the ability of growth and resistance of B. braunii against low pH. Under low nitrogen conditions, the growth of B. braunii cells would not continue for a longer time. B. braunii which grow in nitrogen depletion medium produced lipid content greater than normal nitrogen. UV-B light mutation also increased the lipid content of B. braunii. At 7 days of incubation, the mutation not only increased lipid content, but also significantly increased the TAG content of B. braunii lipids

<em>Calophyllum inophyllum</em>: Beneficial Phytochemicals, Their Uses, and Identification

Calophyllum inophyllum Linn. is one type of mangrove plant. This plant is commonly called nyamplung. This plant is abundant in Indonesia and has many properties that can be exploited from the roots, stems, and leaves to the seeds. All parts of this plant can be useful for human needs. Its oil is generally only used as biodiesel feedstock. The aim of this chapter is to discuss the identification and the uses of phytochemicals contained in C. inophyllum leaves. There are various kinds of phytochemicals contained in C. inophyllum leaves, such as triterpenoids, steroids, flavonoids, coumarins, xanthones, fatty acids, esters, alkenes, ethers, and alicyclic compounds. They have benefits to health, such as anticancer, anti-HIV, antiviral, antitumor, anti-inflammatory, antimicrobial, antineoplastic, antiplatelet, antipsychotics, antioxidant, antiaging, antileukemic, antimalarial, anticoagulant, antifeedant, analgesic, photoprotective, molluscicidal, and piscicidal agents. Extraction is a famous method for isolating phytochemicals in C. inophyllum leaves, based on the solvent polarity index

Pra Desain Pabrik Biodiesel dari Crude Calophyllum Inophyllum Oil (CCIO) dengan Metode Kombinasi Microwave Asisted Extraction - Batchwise Solvent Extraction

Beberapa tahun belakangan ini, persoalan energi telah menjadi permasalahan yang krusial baik di Indonesia maupun dunia, sehingga terjadi peningkatan harga bahan bakar minyak (BBM). Ketergantungan manusia terhadap bahan bakar fosil (BBF) menyebabkan cadangan sumber energi tersebut makin lama semakin berkurang. Nyamplung (Calophyllum inophyllum) merupakan spesies tanaman mangrove dari famili Calophyllaceae. Beberapa keunggulan biodiesel yang dihasilkan dari nyamplung adalah rendemen minyak nyamplung tergolong tinggi yaitu 40-73%. Terdapat tiga tahapan utama dalam pembuatan pabrik biodiesel dari Biji Nyamplung (CCIO) yaitu Persiapan bahan baku pre-treatment, proses pemurnian dan proses pembuatan Biodiesel. Pada pabrik ini proses pemurnian menggunakan metode kombinasi Microwave Assisted Extraction (MAE) - Batchwise Solvent Extraction (BSE). Produk yang dihasilkan dari pabrik ini adalah metil ester (biodiesel) sebagai produk utama dan gliserol sebagai produk samping. Pabrik ini berkapasitas 100.000 ton/tahun dengan operasi selama 24 jam per hari dengan hari kerja 330 hari per tahun. Sumber investasi pabrik Biodiesel dari Biji Nyamplung berasal dari 30% dana pribadi dan 70% dana pinjaman dari Bank (Bank BRI). Dengan perincian analisa ekonomi sebagai berikut, Total Capital Investment (TCI): Rp 266.212.519.031, Net Present Value (NPV): Rp 229.322.898.704, Internal Rate of Return (IRR): 23,8 %, Pay Out Time (POT): 3,97 tahun, Break Event Point (BEP): 49,36 % Kapasitas total. Sehingga dengan hasil tersebut dinilai bahwa pabrik ini layak untuk didirikan

Performance of MoS2 Coated Gears Exposed to Humid Air During Storage

The purpose of this work was to study the effect of exposure to humid air on the durability of a molybdenum disulfide dry film lubricant applied to spur test gears and subsequently tested in vacuum environment. This study was motivated by the James Webb Space Telescope (JWST) Mission. Some moving mechanical assembles of the JWST have been exposed to humid air during storage as a subassembly and after integration into a higher-level assembly. molybdenum disulfide dry film lubricant was applied to steel spur test gears and subsequently tested in vacuum environment. One-half of the gears had essentially zero time exposure to humid air prior to testing, and the other half were exposed to humid air of 57 percent relative humidity for exposure durations up to 77 days prior to testing. All tests were completed at the same constant torque and speed. On average, the film durability, as measured by the number of pinion revolutions, was shorter for gears exposed to humid air compared to those with zero exposure. For the unexposed gears, the durability ranged from 53,300 to 190,300 pinion revolutions with an average value of 100,200 and a median value of 83,500 revolutions. For the exposed gears, the durability ranged from 21,000 to 84,700 pinion revolutions with an average value of 64,900 and a median value of 68,800 revolutions. Using the unexposed gears as a baseline, the exposure reduced the average durability by 35 percent and the median value of durability by 18 percent. Red-brown coloration was noted on some of the gear teeth that had been exposed to humid air. The colored regions appeared as soon as 17 days after exposure to humid air. SEM inspections showed that at least some of these colored areas included material raised above the surrounding molybdenum disulfide film