Dynamic Modelling and Experimental Validation of a Domestic Refrigeration Cycle

Performance analysis and design optimization of refrigerators are primarily carried out by time-consuming experiments. The current study presents an alternative method of analysing refrigerators through modelling of the cooling cycle using a software called Dymola, based on an object-oriented programming language, called Modelica. The main components of a domestic refrigerator (compressor, condenser, evaporator, cabinet and capillary tube-suction-line heat exchanger) are first modelled and validated individually. The full dynamic refrigeration cycle model is created afterwards. Both the simulations and the experiments have been conducted using R600a as the refrigerant with on-and off-modes of the reciprocating, single speed compressor. To represent the dynamic cyclic behaviour of the refrigerator, an algorithm block is also included. The algorithm controls the operation using two set-point temperatures of the cabinet. Experiments have been carried out on a single door refrigerator having an interior volume of 343 litres for the validation of the one-dimensional dynamic model. Results show that the cabinet air, evaporation temperature, condensation temperature, power and energy values deviate from experimental values by less than 2°C and 2% respectively. The dynamic modelling is found to be in good agreement with the experiments in the on mode of the compressor and a promising and rapid tool to represent the transient behaviour of the refrigerator.

Comparison of the efficacy of supraglottic airway devices in low-risk adult patients: a network meta-analysis and systematic review

Numerous supraglottic airway device (SADs) have been designed for adults; however, their relative efficacy, indicated by parameters such as adequacy of sealing, ease of application, and postinsertion complications, remains unclear. We conducted a systematic review and network meta-analysis to evaluate the efficacy of various SADs. We searched electronic databases for randomized controlled trials comparing at least two types of SADs published before December 2019. The primary outcomes were oropharyngeal leak pressure (OLP), risk of first-attempt insertion failure, and postoperative sore throat rate (POST). We included 108 studies (n = 10,645) comparing 17 types of SAD. The Proseal laryngeal mask airway (LMA), the I-gel supraglottic airway, the Supreme LMA, the Streamlined Liner of the Pharynx Airway, the SoftSeal, the Cobra Perilaryngeal Airway, the Air-Q, the Laryngeal Tube, the Laryngeal Tube Suction II, the Laryngeal Tube Suction Disposable, AuraGain, and Protector had significantly higher OLP (mean difference ranging from 3.98 to 9.18 cmH2O) compared with that of a classic LMA (C-LMA). The Protector exhibited the highest OLP and was ranked first. All SADs had a similar likelihood of first-attempt insertion failure and POST compared with the C-LMA. Our findings indicate that the Protector may be the best SAD because it has the highest OLP.Systematic review registration PROSPERO: CRD42017065273.

Perubahan Kadar Saturasi Oksigen pada Pasien Dewasa yang Dilakukan Tindakan Suction Endotrakeal Tube di Ruang ICU RSUD Ulin Banjarmasin

Handling for airway obstruction due to excessive accumulation of secretions can be done with suction, suction is done by inserting suction catheter tube into endotracheal tube or tracheostomy which aims to liberate airway. Endotracheal suction in critically ill patients can cause increased intracranial pressure, brain swelling and systemic hypoxemia may even lead to death. The easiest way to find out hypoxemia is by looking at the patient's oxygen saturation of peripheral oxygen saturation is a presentation of hemoglobin binds with oxygen in the arteries with normal values between 95-100%.This research aims to analyze changes in oxygen saturation levels of patients before, during and after the suction endotracheal tube performed in Intensive Care Unit Ulin Banjarmasin Hospital. This research method is quantitative with comparative design. The population in this research are all patients who had endotracheal tube and suction was done, the sample in the research are 25 respondents with Probability sampling technique, analyzed by paired T test.The results of this research at the time of 1 "-3" average oxygen saturation change of 0-1%, while 4"- 6" on average by 2-3% and at 7 "-10" on average by 2-5% . Paired T-test results showed there was a change in oxygen saturation level in adult patients performed endotracheal tube suction in Intensive Care Unit Ulin Banjarmasin Hospital.

372 Effect of rumen fluid collection methodology on extent and variance of in vitro dry matter disappearance and interaction with substrate and incubation time

The objective was to evaluate the interaction of rumen fluid collection methodology, substrate, and incubation time on the extent and variance of in vitro dry matter disappearance (IVDMD). A 4×2×2 factorial design was used to test the interaction between rumen fluid collection methodology, substrates (hay and silage), and incubation time-points (24 and 48 h). Four methods of rumen fluid collection were evaluated: stomach tube (TUBE), suction strainer through rumen cannula (STRN), ruminal contents collected through cannula and squeezed through cheesecloth (SQZ), and ruminal contents blended for 1 minute and squeezed through cheesecloth (BSQZ). Four replications of each treatment were used and repeated in three periods. A methodology by substrate interaction (P < 0.01) was observed for pH; hay had a greater pH than silage and the magnitude of this difference was greatest for STRN. A tendency for a methodology by substrate interaction (P = 0.06) was observed for ammonia. For TUBE ammonia was greater (P < 0.01) with hay while substrate did not affect ammonia for BSQZ, SQZ and STRN. A methodology by time interaction was observed (P < 0.01) for ammonia; TUBE was least at 24 h, but TUBE and BSQZ were lesser (P ≤ 0.01) than STRN and SQZ at 48 h. A tendency for a methodology by substrate interaction (P = 0.08) was observed in IVDMD; silage had greater IVDMD than hay and the magnitude of this difference was greatest for TUBE. Collection methodology affected (P < 0.01) IVDMD. The greatest IVDMD was observed for STRN (64.7%), with BSQZ (59.1%) and SQZ (57.7%) being intermediate and TUBE (54.3%) being the least. A tendency for a methodology by substrate interaction (P = 0.11) was observed for variation in IVDMD; silage had greater variation than hay for TUBE. Rumen fluid collection methodology affects IVDMD and may depend on substrate.

Pengaruh Tindakan Suction ETT Terhadap Kadar Saturasi Oksigen Pada Pasien Gagal Nafas di Ruang ICU dan IGD Rumah Sakit Umum Daerah Prabumulih Tahun 2017

Pengaruh Tindakan Suction ETT Terhadap Kadar Saturasi Oksigen Pada Pasien Gagal Nafas di Ruang ICU dan IGD Rumah Sakit Umum Daerah Prabumulih Tahun 2017 (Effect of ETT Suction Measures on Oxygen Saturation Rate in Patients Failed Breath in ICU and IGD Room at Prabumulih Regional General Hospital 2017) Yuliani.1, Siti Romadoni.2, Imardiani3 1Mahasiswa STIKes Muhammadiyah Palembang, Palembang, Indonesia 2Dosen STIKes Muhammadiyah Palembang, Palembang, Indonesia 3Dosen STIKes Muhammadiyah Palembang, Palembang, Indonesia Program Studi Ilmu Keperawatan Sekolah Tinggi Ilmu Keperawatan Muhammadiyah Palembang e-mail : [email protected] /0813-672 680 75 ABSTRAK Latar belakang: Pasien yang terpasang Endotracheal Tube (ETT) secara umum memiliki respon tubuh yang kurang baik untuk mengeluarkan benda asing sehingga pasien akan mengalami peningkatan dan penumpukan sekret. Ketidakmampuan untuk membersihkan sekresi atau obstruksi dari saluran napas untuk mempertahankan bersihan jalan napas, hal inilah yang menyebabkan kadar saturasi oksigen yang dialami responden mengalami perubahan. Tujuan Penelitian: Untuk mengetahui pengaruh tindakan suction Endotracheal Tube (ETT) terhadap kadar saturasi oksigen pada responden di Rumah Sakit Umum Daerah Prabumulih. Metode Penelitian: Rancangan penelitian ini adalah Pre-experemintaldesign. Teknik sampling yang digunakan adalah nonprobability sampling dengan cara consecutive sampling dengan jumlah sampel 13 responden. Penelitian ini dilaksanakan mulai 5 April – 05 Mei 2017. Pengumpulan data dilakukan dengan cara melihat hasil pengukuran kadar saturasi oksigen dengan menggunakan alat oksimeter pulse pada saat sebelum dan sesudah diberikan tindakan suction.Hasil: sebelum dilakukan suction, kadar saturasi oksigen responden rata-rata sebesar 97,77% dan sesudah saturasi menjadi 96,51%. Terdapat perbedaan yang signifikan antara kadar saturasi oksigen pada saat sebelum dan sesudah diberikan tindakan suction pada pasien yang terpasang ETT di Ruang ICU dan IGD RSUD Prabumulih dengan nilai t hitung sebesar 3,949 >t tabel = 2,179. Kesimpulan: Ada pengaruh tindakan suction terhadap kadar saturasi oksigen pada saat sebelum dan sesudah diberikan tindakan suction pada pasien yang terpasang ETT di Ruang ICU dan IGD RSUD Prabumulih p value = 0,002. Disarankan kepada pihak rumah sakit untuk melakukan pengukuran tanda-tanda vital sebelum melakukan tindakan suction serta dapat melakukan tiga kali pengukuran untuk keakuratan kadar saturasi oksigen. Kata kunci : Saturasi Oksigen, Endotracheal Tube, Suction