• Title/Summary/Keyword: temperature and humidity chamber

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Photostability evaluation of Jawarishe Jalinoos

  • Shahnawaz, Shahnawaz;Rahman, Khaleequr;Sultana, Arshiya;Sultana, Shabiya
    • CELLMED
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    • v.11 no.4
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    • pp.18.1-18.8
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    • 2021
  • Jawarishe Jalinoos (JJ) is an orally used formulation available in semisolid dosage form, prepared with powdered plant materials mixed in honey or sugar syrup. It has many admirable pharmacological effects and used in Unani medicine to treat various acute and chronic disorders since ancient times. The ICH Harmonised Tripartite Guideline stated that photostability testing should be an essential part of stability testing to confirm that light exposure does not result in an unacceptable change in drugs substance and finished products. To date, the effect of light on JJ is not studied, in this study photostability evaluation of JJ was carried out. The test sample was manufactured with genuine ingredients in the in-door pharmacy of the National Institute of Unani Medicine. JJ was packed in two transparent polyethylene terephthalate airtight containers. The first sample was analysed at zero-day and the second sample was placed in a stability chamber subjected to light challenge with an overall illumination of 1.2 million lux hours combined with near ultraviolet energy of 200-watt hours per square meter by using option 2, along with 30±2℃ temperature and relative humidity 70±5%. Analysis of both finished products showed no considerable changes in organoleptic characters. Less than 5% variation was observed in physicochemical parameters. HPTLC fingerprinting showed justifiable variation. Microbial load and specific counts were within the limit prescribed by WHO. As no unacceptable changes were noted in JJ subjecting to light challenge, it is concluded that JJ is a photostable Unani compound formulation.

A Study on Compressive Strength of Concrete Exposed to Evaporation Immediately After Casting (성형직후 증발작용을 받은 콘크리트의 강도에 대한 연구)

  • 오무영
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.16 no.4
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    • pp.3545-3554
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    • 1974
  • The objective of this study was to investigate the characteristics of the evaporation rate, the plastic shrinkage and the compressive strength of concrete exposed to a rapid evaporation environment immediately after casting. Drying of concrete were conducted under a controlled chamber in which the temperature was mainfoimed at 30 ${\pm}$1$^{\circ}C$, the relative humidity 22 ${\pm}$1 percent, and the wind velocity 7 ${\pm}$1 m/sec. The compressive strength of concrete was tested after 28 days of standard curing. The results obtained are as follows: 1. The evaporation rate was the highest at the very beginning, was decreased as the drying progresses, and was kept almost constant after 6 hours. 2. The shrinkage of concrete was changed in three different rates for the concrete mixture having its slump vallue between 3.0cm and 7.5cm. 3. The plastic shrinkage was ended within 5 or 6 hours after casting, regardless of the water cement ratio. 4. The shrinkage was increased within the limit of slump values between 3.0cm and 7.5cm as the water-cement ratio was increased. 5. The evaporation was kept on even after the plastic shrinkage was ended. 6. Within the limit of good workability (slump value between 4.5cm and 7.5cm), the compressive strength of concrete was increased when the shrinkage rate was slow but it was decreased when the rate was rapid 7. From the result of this study it is recommended that (1) the water-cement ratio should be less as long as the workability of concrete is allowable; (2) the evaporation should be prevented at least for 4 hours after casting concrete.

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Effect of Silica Gel on Food Dehydration of Onion by Solar Energy (태양열(太陽熱)을 이용(利用)한 식품건조(食品乾燥)에서 Silica Gel의 활용효과(活用效果))

  • Jeon, Byeong Seon;Yoon, Han Kyo;Chang, Kyu Seob
    • Korean Journal of Agricultural Science
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    • v.10 no.1
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    • pp.156-165
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    • 1983
  • This experiment was carried out to elucidate the drying characteristics of onion and dehumidifying effect of air using the silica gel and to reuse it by solar collector. The results were summarized as follows. 1. It takes 14hours to regenerate to silica gel of 8% moisture content from saturated silica gel in conditions of $28^{\circ}c$ temperature and 55% relative humidity. 2. When sample was recycled through solar collector, the result of drying was 1/2 times more efficient than that of mat drying. 3. Average thermal efficiency of solar collector was 25% during the experimental period. 4. Browning extent was reduced to 1/2 times at heated air blow drying system using drying chamber.

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Characterization of Volatile Organic Compounds Emission from Interior Materials of Railway Passenger Cabin (철도차량용 내장재의 휘발성유기화합물 방출특성 분석)

  • Cho, Young-Min;Park, Duck-Shin;Kwon, Soon-Bark;Park, Eun-Young
    • Journal of the Korean Society for Railway
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    • v.11 no.2
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    • pp.182-187
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    • 2008
  • The environmental significance of indoor air quality is gaining more attention. Especially, the contamination of indoor air by volatile organic chemicals (VOCs) has become a serious environmental concern. We investigated the VOCs emissions from some interior materials used in the conventional railway passenger cabin. The seat cover and the flooring of cabins were used as testing materials, and they were put in a clean environmental chamber. The temperature and relative humidity was kept at $25{\pm}1^{\circ}C$ and $50{\pm}5%$, respectively. It was found that these interior materials emitted significant amount of VOCs under constantly ventilated condition. The flooring emitted more halogenated VOCs than the seat cover, because it is made of PVC, which contains many chlorine atoms. However, the emission gradually decreased over time. Because the VOCs emission from interior materials may threaten the health of passengers in the cabin, interior materials emitting less VOCs should be used.

Study on Characteristics of Car Air-con Compressor Under Bench System Fuel Economy Simulation Condition (벤치 연비 모사 조건에서 차량용 에어컨 압축기의 특성에 관한 연구)

  • Yoo, Seong-Yeon;Kim, Young-Shin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.7
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    • pp.705-710
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    • 2012
  • In this study, an experiment on an air conditioning test bench was performed to verify the possibility of fuel economy simulation for the SC03 mode, North America fuel economy certification mode with a/c on condition, one of the vehicle fuel economy evaluation modes. The air conditioning test bench used in this study had each chamber simulating the actual vehicle air conditioning system and the controlling temperature, humidity, and air flow velocity to reproduce environmental conditions. Reliable results were obtained about the compressor RPM and inlet air velocity in front of the condenser corresponding to vehicle speed and air velocity in front of the vehicle, respectively, in the simulation of the SC03 mode, previously performed in CWT, in an air conditioning test bench. It was also discovered that there was a distinct difference in the fuel economy depending on the difference in the compressor displacement in the simulation test of the SC03 mode in the air conditioning test bench under various displacement conditions of the compressor.

Effect of Super Absorbent Polymer on Germination and Growth of Safflower and Amaranth Sprouts (고흡수성 합성고분자가 홍화 및 아마란스 새싹의 발아 및 생육에 미치는 영향)

  • Jang, Seong-Nam;Lee, Ga-Oun;Lee, Seung-man;Yun, Jae Gil;Shin, Hyunsuk;Son, Ki-Ho
    • Journal of Bio-Environment Control
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    • v.30 no.1
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    • pp.37-45
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    • 2021
  • This study was conducted to evaluate the growth characteristics, phenolic concentration and antioxidant capacity of safflower (Carthamus tinctorius L.) and amaranth (Amaranthus spp.) sprout and investigate the possibility of using super absorbent polymer (SAP) as a medium in hydroponic cultivation in a plant factory. The control was used a commercial sprout cultivation tool (19 × 14 × 9 cm, W × D × L), and a treatment (SAP) was added on the cultivation tool to compare the effect of SAP. Safflower sprouts were immersed in a distilled water at 30 ℃ for 5 hours, and then grown in a plant growth chamber. The temperature and relative humidity were maintained at 25 ± 1℃ and 70 ± 4%, respectively. The light condition was maintained at 35 ± 6 μmol·m-2·s-1 (12h). Amaranth sprouts were grown in a plant growth chamber maintained with temperature of 25 ± 2℃, relative humidity of 70 ± 5% and light condition of 188 ± 10 μmol·m-2·s-1 (16h). A physical and chemical characteristic of SAP, and a germination rate, growth characteristics and secondary metabolites were analyzed in both safflower and amaranth. There was no significant effect on SAP in a germination rate, growth and secondary metabolites of safflower compared to the control, whereas amaranth grown under SAP was higher in germination rate, dry weight, phenolic concentration, and antioxidant capacity compared to the control. As a result, this study was suggested that cultivation of sprouts using SAP would be possible in a plant factory, and further studies on SAP on plant physiological response are required.

Cold Storage Characteristics of Early Variety of Citrus unshiu Produced in Cheju with Various Treatments (처리조건에 따른 조생온주밀감의 저온저장 특성)

  • Yang, Young-Taek;Song, Sang-Cherl;Kim, Seong-Hak;Kim, Ji-Yong;Koh, Jeong-Sam
    • Applied Biological Chemistry
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    • v.40 no.2
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    • pp.117-122
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    • 1997
  • The conditions of cold storage of Citrus unshiu Marc. var. miyagawa produced in Cheju were investigated. Compared to the citrus fruits stored at room temperature, the content of soluble solids, total sugar, vitamin C and specific gravity decreased slightly on the fruits stored at $4^{\circ}C$ and 87% relative humidity. Decay ratio and weight loss were below 10% on keeping freshness relatively till late of March during cold storage. Weight loss, decrease of firmness and soluble solids occured gradually during cold storage. Nevertheless seal-packaging with 0.02 mm LDPE film or wax-coating of citrus fruits were effective on weight loss and appearance, decay ratio increased for long-term storage. It was needed to control humidity in cold chamber for preventing from decay and weight loss. Edible part ratio was decreased gradually by respiration, and peel and tissue of fruits were softened slightly by 60 days of cold storage. Decay ratio and weight loss of full-ripened citrus fruits were little during the storage for 100 days, compared to the fruits harvested early. Appearance and taste of citrus fruits stored for 4 month were good relatively, but decay occured rapidly on seal-packaging fruits putting out of cold room for a few days. Because of the difficulty of long-term storage for early variety of Citrus unshiu, the conditions and periods of cold storage would be determined after considering the physicochemical properties of fruits.

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Preliminary Study on Effect of the Field Correlation Factor for Increasing of the Accuracy in a Direct Reading Instruments on Photoionization Detector for Total Volatile Organic Compounds (총휘발성유기화합물 측정 직독식장비 정확도 향상을 위한 현장보정계수 활용 연구)

  • Sungho Kim;Gwangyong Yi;Sujin Kim;Hae Dong Park
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.34 no.1
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    • pp.67-76
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    • 2024
  • Objectives: Direct reading instruments (DRIs) are widely used by industrial hygienists and other experts for preliminary survey and identifying source locations in many industrial fields. Photoionization detectors (PIDs), which are a form of hand-held portable DRIs, have been used for a variety of airborne vaporized chemicals, especially evaporated hydrocarbon solvents. The benefits of PIDs are high sensitivity between each chemical, competitive price, and portability. With the goal of increasing the accuracy of logged PID concentrations, previous studies have performed tests for the assessment of single chemical compounds, not mixtures. The purpose of this preliminary study was to measure mixtures with a PID and charcoal tube at the same time and compare the accuracy between them. Methods: A chamber test was implemented with different mixtures of hydrocarbon chemicals (acetone, isopropyl alcohol, toluene, m-xylene) and levels in the range of 14 to 864 ppm. Three PIDs and charcoal tubes were connected to the chamber and measured the chemical mixtures simultaneously. A comparison of accuracy and the PID group of concentrations with manufacture correction factor (M_CF) and field correction factor (F_CF) applied was performed. Results: The accuracy of the PID concentrations data-logged from the PID did not meet the accuracy criteria except for the mixture level B and C logged from PID No. 2, which was 18% of all tests for meeting accuracy criteria. The mean and standard deviation (SD) of concentration (ppm) of the charcoal tube followed by each mixtures' level were 10.37±0.26, 155.33±5.28, 300.80±11.65, and 774.93±22.65, respectively. When applying F_CF into the PID concentrations, the accuracy increased by nearly 82%. However, in the case of M_CF, none met the accuracy criterion. Between the PID there were differences of logged concentrations. Conclusions: In this preliminary study, the concentration of a logged PID with F_CF applied was a better way to increase accuracy compared to applying M_CF. We suggest that additional research is necessary to consider environmental factors such as temperature and humidity.

Carbonation Evaluation After CO2 Curing of Concrete Bricks Using Industrial by-products (산업부산물을 사용한 콘크리트 벽돌의 CO2 양생 후 탄산화 평가 )

  • Hoon Moon;Namkon Lee;Jung-Jun Park;Gum-Sung Ryu;Gi-Joon Park;Indong Jang
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.4
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    • pp.373-380
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    • 2023
  • This study investigated the carbonation of concrete brick cured in a CO2 environment for the utilization of CO2 captured in power plants. Concrete brick specimens were produced with electric arc furnace reducing slag (ERS) and electric arc furnace oxidizing slag (EOS), and cured for 3 days in a CO2 chamber with a concentration of 20 % or in a constant temperature and humidity chamber. The weight change, compressive strength, flexural strength and carbonation depth of concrete bricks were measured. From the results, it was found that when subjected to CO2 curing, CO2 was absorbed at the level of 2.4 % of the weight of the specimen. The specimen incorporating ERS showed the highest carbonation depth, and satisfied KS F4004 standards for the concrete brick. Therefore, it is expected that the captured CO2 can be utilized in the CO2 curing process of concrete brick.

Deposition and Characterization of Antistiction Layer for Nanoimprint Lithography by VSAM (Vapor Self Assembly Monolayer) (기상 자기조립박막 법을 이용한 나노임프린트용 점착방지막 형성 및 특성평가)

  • Cha, Nam-Goo;Kim, Kyu-Chae;Park, Jin-Goo;Jung, Jun-Ho;Lee, Eung-Sug;Yoon, Neung-Goo
    • Korean Journal of Materials Research
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    • v.17 no.1
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    • pp.31-36
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    • 2007
  • Nanoimprint lithography (NIL) is a new lithographic method that offers a sub-10nm feature size, high throughput, and low cost. One of the most serious problems of NIL is the stiction between mold and resist. The antistiction layer coating is very effective to prevent this stiction and ensure the successful NIL results. In this paper, an antistiction layer was deposited by VSAM (vapor self assembly monolayer) method on silicon samples with FOTS (perfluoroctyltrichlorosilane) as a precursor for making an antistiction layer. A specially designed LPCVD (low pressure chemical vapor deposition) was used for this experiment. All experiments were achieved after removing the humidity. First, the evaporation test of FOTS was performed for checking the evaporation temperature at low pressure. FOTS was evaporated at 5 Tow and $110^{\circ}C$. In order to evaluate the temperature effect on antistiction layer, chamber temperature was changed from 50 to $170^{\circ}C$ with 0.1ml of FOTS for 1 minute. Good hydrophobicity of all samples was shown at about $110^{\circ}$ of contact angle and under $20^{\circ}$ of hysteresis. The surface energies of all samples calculated by Lewis acid/base theory was shown to be about 15mN/m. The deposited thicknesses of all samples measured by ellipsometry were almost 1nm that was similar value of the calculated molecular length. The surface roughness of all samples was not changed after deposition but the friction force showed relatively high values and deviations deposited at under $110^{\circ}$. Also the white circles were founded in LFM images under $110^{\circ}$. High friction forces were guessed based on this irregular deposition. The optimized VSAM process for FOTS was achieved at $170^{\circ}C$, 5 Torr for 1 hour. The hot embossing process with 4 inch Si mold was successfully achieved after VSAM deposition.