scholarly journals Analisis Laju Penurunan Temperatur di Dalam Ruangan Menggunakan AC Low Watt 0,5 HP

2021 ◽  
Vol 4 (01) ◽  
pp. 25-31
Author(s):  
Khambali Khambali ◽  
Listiyono Listiyono
Keyword(s):  
Room Temperature ◽  
Temperature Drop ◽  
Reduction Rate ◽  
Independent Variables ◽  
Temperature Reduction ◽  
Temperature Conditions ◽  
Significant Difference ◽  
Cooling Speed ◽  
Heat Absorb ◽  
Compressor Power

Heat absorb ability split AC is the most important factor in the cooling speed on room temperature. The rate of temperature drop is determined by many factors, including compressor power. Nowadays, there are many Split AC are produced that have low power (low Watt), so that research is needed to determine the cooling speed in a room. This study uses a low watt split AC with a power of 0.5 HP. The distance from the evaporator and the outside temperature are used as independent variables, while the rate of temperature reduction or cooling speed in the room is used as the dependent variable. The results showed that the distribution of room temperature and the rate of temperature reduction in the room varied based on the position of the distance to the location of the AC Split Low Watt. The lowest temperature and reduction rate in the room occurs at a distance of 2 m and 3 m in front of the AC location. The outside temperature or the temperature around the location of the AC condenser affects the temperature distribution at each distance in front of the AC. When the outside temperature is low, the temperature conditions at a distance of 1 m, 4 m, and 5 m have a significant difference. While the high outside temperature conditions, the temperature at a distance of 1 m, 4 m, and 5 m, namely the positions close to the wall, is almost the same.   Kata kunci: AC, split, low watt, evaporator

scholarly journals Changes in Bond Strength and Topography for Y-TZP Etched with Hydrofluoric Acid Depending on Concentration and Temperature Conditions

Medicina ◽  
2020 ◽  
Vol 56 (11) ◽  
pp. 568
Author(s):  
Hyo-Eun Kim ◽  
Myung-Jin Lim ◽  
Mi-Kyung Yu ◽  
Kwang-Won Lee
Keyword(s):  
Surface Roughness ◽  
Bond Strength ◽  
Hydrofluoric Acid ◽  
Room Temperature ◽  
High Surface ◽  
Tetragonal Zirconia ◽  
Resin Cement ◽  
Grain Structure ◽  
Temperature Conditions ◽  
Significant Difference

Background and objectives: This study aimed to investigate the change in bond strength between resin cement and tetragonal zirconia polycrystalline stabilized with 3 to 8 mol% yttrium oxide (Y-TZP) and observe the topographical change of the Y-TZP surface when etched with hydrofluoric acid (HF) solution under different concentration and temperature conditions. Materials and Methods: Non-etched sintered Y-TZP specimens under two different temperature conditions (room temperature and 70–80 °C, respectively), were used as a control, while experimental groups were etched with 5%, 10%, 20%, and 40% HF solutions for 10 min. After zirconia primer and MDP-containing resin cement were applied to the Y-TZP surface, the shear bond strength (SBS) of each experimental group was measured. Results: Under room temperature conditions, the highest SBS value was measured in the 40% HF etching group, representing a significant deviation from the other groups (p < 0.05). In the 70–80 °C tests, the 40% HF etching group also had the highest SBS value, but there was no significant difference when compared to the 20% HF etching group (p > 0.05). From SEM and AFM observations, the HF solution increasingly dissolved the Y-TZP surface grain structure as the concentration and application temperature rose, resulting in high surface roughness and irregularities. Conclusions: Pretreating with either 20% HF solution at 70–80 °C or 40% HF solution at room temperature and 70–80 °C effectively acid etched the Y-TZP surface, resulting in more surface roughness and irregularities. Accounting for the concentration and temperature conditions of the HF solution, using 40% HF solution at room temperature will result in improvements in adhesion between resin cement and Y-TZP.

scholarly journals Reduction Mechanism of Fine Hematite Ore Particles in Suspension

2021 ◽  
Author(s):  
Zhiyuan Chen ◽  
Christiaan Zeilstra ◽  
Jan van der Stel ◽  
Jilt Sietsma ◽  
Yongxiang Yang
Keyword(s):  
Particle Size ◽  
Temperature Drop ◽  
Reduction Rate ◽  
Reduction Process ◽  
Reciprocal Relationship ◽  
Drop Tube ◽  
Surface Nucleation ◽  
Order Of Magnitude ◽  
Relationship Of ◽  
Kinetics Of

AbstractIn order to understand the pre-reduction behaviour of fine hematite particles in the HIsarna process, change of morphology, phase and crystallography during the reduction were investigated in the high temperature drop tube furnace. Polycrystalline magnetite shell formed within 200 ms during the reduction. The grain size of the magnetite is in the order of magnitude of 10 µm. Lath magnetite was observed in the partly reduced samples. The grain boundary of magnetite was reduced to molten FeO firstly, and then the particle turned to be a droplet. The Johnson-Mehl-Avrami-Kolmogorov model is proposed to describe the kinetics of the reduction process. Both bulk and surface nucleation occurred during the reduction, which leads to the effect of size on the reduction rate in the nucleation and growth process. As a result, the reduction rate constant of hematite particles increases with the increasing particle size until 85 µm. It then decreases with a reciprocal relationship of the particle size above 85 µm.

An efficient construction of CN bond under catalyst‐free and room temperature conditions

2021 ◽  
Vol 58 (5) ◽  
pp. 1179-1191
Author(s):  
Jinpeng Zhang ◽  
Jing Liu ◽  
Lei Dai ◽  
Yuqian Ge ◽  
Linlin Xu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Catalyst Free ◽  
Temperature Conditions ◽  
Efficient Construction

Room-Temperature Reduction of Sulfur Hexafluoride with Metal Phosphides

2021 ◽  
Author(s):  
Blake Stanley Norman Huchenski ◽  
Alexander William Harrison Speed
Keyword(s):  
Alkali Metal ◽  
Room Temperature ◽  
Sulfur Hexafluoride ◽  
Temperature Reduction ◽  
Metal Phosphides

Upon treatment with sulfur hexafluoride, alkali metal diphenyl or dicyclohexyl phosphides are oxidized within seconds to tetraphenyl or tetracyclohexyl diphosphines. When bulky di-tert-butylphosphide is employed, fluorophosphine intermediates are detected. This...

Ultrafast room-temperature reduction of graphene oxide to graphene with excellent dispersibility by lithium naphthalenide

Carbon ◽  
2013 ◽  
Vol 63 ◽  
pp. 165-174 ◽  
Author(s):  
Haesol Jung ◽  
Seung Jae Yang ◽  
Taehoon Kim ◽  
Jong Hun Kang ◽  
Chong Rae Park
Keyword(s):  
Graphene Oxide ◽  
Room Temperature ◽  
Temperature Reduction

scholarly journals Evaluation of Respiratory Resistance as a Predictor for Oral Appliance Treatment Response in Obstructive Sleep Apnea: A Pilot Study

2021 ◽  
Vol 10 (6) ◽  
pp. 1255
Author(s):  
Hiroyuki Ishiyama ◽  
Masayuki Hideshima ◽  
Shusuke Inukai ◽  
Meiyo Tamaoka ◽  
Akira Nishiyama ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Pilot Study ◽  
Reduction Rate ◽  
Oral Appliance ◽  
Respiratory Resistance ◽  
Obstructive Sleep ◽  
Respiratory Event ◽  
Significant Difference ◽  
Treatment Responses

The aim of this study was to determine the utility of respiratory resistance as a predictor of oral appliance (OA) response in obstructive sleep apnea (OSA). Twenty-seven patients with OSA (mean respiratory event index (REI): 17.5 ± 6.5 events/h) were recruited. At baseline, the respiratory resistance (R20) was measured by impulse oscillometry (IOS) with a fitted nasal mask in the supine position, and cephalometric radiographs were obtained to analyze the pharyngeal airway space (SPAS: superior posterior airway space, MAS: middle airway space, IAS: inferior airway space). The R20 and radiographs after the OA treatment were evaluated, and the changes from the baseline were analyzed. A sleep test with OA was carried out using a portable device. The subjects were divided into Responders and Non-responders based on an REI improvement ≥ 50% from the baseline, or REI < 5 after treatment, and the R20 reduction rate between the two groups were compared. The subjects comprised 20 responders and 7 non-responders. The R20 reduction rate with OA in responders was significantly greater than it was in non-responders (14.4 ± 7.9 % versus 2.4 ± 9.8 %, p < 0.05). In responders, SPAS, MAS, and IAS were significantly widened and R20 was significantly decreased with OA (p < 0.05). There was no significant difference in non-responders (p > 0.05). A logistic multiple regression analysis showed that the R20 reduction rate was predictive for OA treatment responses (2% incremental odds ratio (OR), 24.5; 95% CI, 21.5–28.0; p = 0.018). This pilot study confirmed that respiratory resistance may have significant clinical utility in predicting OA treatment responses.

Abstract 14721: Impact of Covid-19 on Cardiology Consultation in Tertiary Care Hospital of a Developing Country

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
ghufran adnan ◽  
Osman Faheem ◽  
Maria Khan ◽  
Pirbhat Shams ◽  
Jamshed Ali
Keyword(s):  
Emergency Department ◽  
Tertiary Care ◽  
Reduction Rate ◽  
Care Hospital ◽  
Chi Square ◽  
Coronary Syndrome ◽  
Significant Difference ◽  
Drastic Increase ◽  
Chi Square Test ◽  
The Difference

Introduction: COVID-19 pandemic has overwhelmed the healthcare system of Pakistan. There has been observation regarding changes in pattern of patient presentation to emergency department (ED) for all diseases particularly cardiovascular. The aim of the study is to investigate these changes in cardiology consultations and compare pre-COVID-19 and COVID-19 era. Hypothesis: There is a significant difference in cardiology consultations during COVID era as compared to non-COVID era. Method: We collected data retrospectively of consecutive patients who visited emergency department (ED) during March-April 2019 (non-COVID era) and March-April 2020 (COVID era). Comparison has been made to quantify the differences in clinical characteristics, locality, admission, type, number, and reason of Cardiology consults generated. Results: We calculated the difference of 1351 patients between COVID and non-COVID era in terms of cardiology consults generated from Emergency department, using Chi-square test. Out of which 880 (59%) are male with mean age of 61(SD=15). Analysis shows pronounced augmentation in number of comorbidities [Hypertension(6%), Chronic kidney disease (6%), Diabetes (5%)] but there was 36% drop in total cardiology consultations and 43% reduction rate in patient’s ED visit from other cities during COVID era. There was 60% decrease in acute coronary syndrome presentation in COVID era, but fortuitously drastic increase (30%) in type II myocardial injury has been noted. Conclusion: There is a remarkable decline observed in patients presenting with cardiac manifestations during COVID era. Lack in timely care could have a pernicious impact on outcomes, global health care organizations should issue directions to adopt telemedicine services in underprivileged areas to provide timely care to cardiac patients.

STUDIES OF PENICILLIN IN PEDIATRICS

PEDIATRICS ◽  
1950 ◽  
Vol 5 (4) ◽  
pp. 664-671
Author(s):  
B. M. KAGAN ◽  
M. NIERENBERG ◽  
D. GOLDBERG ◽  
A. MILZER
Keyword(s):  
Intramuscular Injection ◽  
Room Temperature ◽  
Serum Levels ◽  
Sesame Oil ◽  
Peanut Oil ◽  
Penicillin G ◽  
Procaine Penicillin ◽  
Pertinent Data ◽  
Significant Difference ◽  
Pediatric Use

Table I summarizes most of the pertinent data in this report on the serum penicillin concentrations 12 and 24 hours after intramuscular injection of K penicillin G in peanut oil and beeswax, which is fluid at room temperature, and of three different procaine penicillin preparations. These three preparations are procaine penicillin G in sesame oil, procaine penicillin G in peanut oil with 2% aluminum monostearate, and procaine penicillin G in water with Na-carboxymethylcellulose. When they were given in a dosage of 8000 u./lb. to infants and children, weighing between 4.5 and 18.0 kg., there was no statistically significant difference in the serum levels obtained. A dosage schedule for these preparations is suggested for pediatric use. The aqueous preparation offers some advantages which are discussed. Experiences are reported which emphasize the necessity of avoiding intravenous administration of all these preparations.

Abstract P189: Method of Cold Saline Storage for Prehospital Induced Hypothermia

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Mitch Kampmeyer ◽  
Clifton W Callaway
Keyword(s):  
Room Temperature ◽  
Prehospital Care ◽  
Rank Test ◽  
Induced Hypothermia ◽  
Ambient Conditions ◽  
Storage Unit ◽  
Cold Saline ◽  
Kaplan Meier ◽  
Significant Difference ◽  
Ambient Room Temperature

Recent research supports the use of cold IV fluid as a method for initiating therapeutic hypothermia in post-cardiac arrest resuscitation. However, prehospital care programs employing this treatment have encountered various difficulties. Barriers to prehospital induced hypothermia protocols include the lack of effective or economically reasonable methods to maintain cold saline in the field. Objective. Determine the time that a standard commercial cooler can maintain two 1-liter normal saline solution (NSS) bags below 4°C in 3 different environments. Methods. Environments simulating an ambulance compartment were created for the experiment. NSS temperatures were continuously recorded inside a standard commercial cooler with or without ice packs (IPs) under one of three scenarios: ambient room temperature (25°C) without (IPs), ambient room temperature with IPs and 50°C ambient temperature with IPs. Four trials under each condition were performed. Time to warm to 4°C was compared using Kaplan-Meier log rank test. Results. In a room temperature environment with IPs, the NSS warmed to 4°C in a mean interval of 29 hrs 53 mins versus in ambient room temperature without IPs (1 hr 21 mins) versus in constant hot environment of 50°C with IPs (10 hrs 50 mins). A significant difference was found between the three environments (log-rank =17.90, dF =2, p =0.0001). Conclusions. Low technology methods in the form of a cooler and IPs can provide cold NSS storage for longer than a full 24 hour shift in a room temperature ambulance. In hot ambient conditions, 4°C NSS can be maintained for nearly 11 hours using this method. This model exhibits an economical, easily deployable cold saline storage unit.

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