Study on optimal adsorption conditions of norfloxacin in water based on response surface methodology

The waste pomelo peel was pyrolyzed at 400 °C to prepare biochar and used as adsorbent to remove norfloxacin (NOR) from simulated wastewater. The adsorption conditions of norfloxacin by biochar were optimized by response surface methodology (RSM). On the basis of single-factor experiment, the adsorption conditions of biochar dosage, solution pH and reaction temperature were optimized by Box-Behnken Design (BBD), and the quadratic polynomial regression model of response value Y1 (NOR removal efficiency) and Y2 (NOR adsorption capacity) were obtained respectively. The results show that the two models are reasonable and reliable. The influence of single factor was as follows: solution pH > biochar dosage > reaction temperature. The interaction between biochar dosage and solution pH was very significant. The optimal adsorption conditions after optimization were as follows: biochar dosage = 0.5 g/L, solution pH = 3, and reaction temperature = 45 °C. The Y1 and Y2 obtained in the verification experiment were 75.68% and 3.0272 mg/g, respectively, which were only 2.38% and 0.0242 mg/g different from the theoretical predicted values of the model. Therefore, the theoretical model constructed by response surface methodology can be used to optimize the adsorption conditions of norfloxacin in water.

Analysis of Prognostic Risk Factors of Sepsis Patients in Intensive Care Unit Based on Data Analysis

In this paper, a data-enabled analysis of the prognostic risk factors of sepsis patients in the intensive care unit is presented. For this purpose, we have selected 220 sepsis patients, preferably those admitted to the intensive care unit for treatment in a tertiary a hospital in Tianjin from June 2018 to June 2019 and received complete data as the research objects, to explore the prognostic risk factors of sepsis patients in the intensive care unit. All patients met the SSC sepsis diagnosis guidelines and recorded the patients’ age, gender, underlying disease, and infection site. Laboratory indicators, such as blood routine, electrolytes, arterial blood gas, liver function, and renal function, were collected within 24 hours of admission. Furthermore, the corresponding specimens were cultured for pathogenic microorganisms according to the site of infection. The LAC value was measured at admission and 24 h after admission, and the 24 h lactate clearance rate was calculated. The Acute Physiological and Chronic Health Status Score II (APACHE-II) and SOFA score were calculated, which were based on the worst value of the index within 24 hours after admission. According to the prognosis of patients during hospitalization, they are divided into two groups: (i) survival group and (ii) death group. We entered all the data into Excel and used SPSS21.0 statistical software for data analysis and processing. Quantitative data are tested for normality. Quantitative data for normal distribution are expressed as mean ± standard deviation, and normal distribution and uniform variance are measured. The factors affecting the prognosis of patients with sepsis were first subjected to a single-factor logistic regression analysis, and a multiple logistic regression analysis was performed on the basis of the significance of the single-factor analysis. The results found that the prognosis of patients with sepsis in the ICU is affected by multiple factors such as underlying diseases, infectious microorganisms, comorbidities, and interventional therapy. APACHE-II score, 24 h lactate clearance rate, ARDS, and DIC are independent risk factors that affect the prognosis of ICU patients.

Experimental study on preparation of fuel by low-temperature pyrolysis of plastic waste combined with desiccated sludge after preforming

Take plastic waste and dried sludge as raw materials, use pressure testing machine and high temperature hot pressing mold to test under different parameters. The effect of raw material ratio, low-temperature pyrolysis temperature, molding pressure and heating time on the physical properties of the molded fuel after low-temperature pyrolysis, such as relaxation density, fall strength, compressive strength and water permeability, are studied. Single factor tests show that the general range of mixed molding parameters is: mixture ratio (dry sludge: composite plastics) 85:15~75:25, temperature 150~250°C, heating time 20~40min, compaction pressure 2~6MPa. Orthogonal test is designed on the basis of single factor test. The results show that the most important factor affecting the relaxation density of molding fuel is molding pressure, the most important factor affecting compressive strength is the ratio of raw materials, and the most important factor affecting water permeability is heating time. The fall strength is less affected by various factors. It is due to the stickiness of the molded plastic after softening, which strengthens the “cohesion” between the raw materials, and will not be explored in the orthogonal experiment. The optimal combination of relaxation density molding parameters is the ratio (dry sludge: composite plastics) 80:20, temperature 250°C, heating time 30min, compaction pressure 6MPa; the optimal combination of compressive strength molding parameters is 75:25, 250°C, 30min, 6MPa; the optimal combination of anti-moisture absorption performance molding parameters is 85:15, 150°C, 30min, 2MPa.

Comparison of Ultrasound Type and Working Parameters on the Reduction of Four Higher Alcohols and the Main Phenolic Compounds

In this paper, studies were conducted by a series of single-factor experiments to investigate the effects of ultrasound types and working parameters on the higher alcohols (HA), phenolic compounds, and color properties of red wine, so as to highlight the importance of the comprehensive consideration on its application. The results indicate that ultrasound devices and working parameters do have some definite influences on the HA of wine; moreover, the ultrasound bath (SB-500DTY) is better than the SCIENTZ-950E and the KQ-300VDE. With the SB-500DTY employed to further investigate its effects on phenols and color properties other than on HA, unexpectedly, some variations of color parameters are opposite to the results ever obtained from other ultrasound conditions. In summary, all these results suggest that both the ultrasound type and parameters should be fully considered or neutralized so as to have a comprehensive evaluation about its application, instead of some contradictory results.

DESIGN OF DEEP-FERTILIZATION MECHANISM WITH DEFORMED GEARS AND PERFORMANCE TESTS

Deep-fertilization mechanism is a key part of deep-fertilization liquid fertilizer applicator. To obtain a good-performance deep-fertilization mechanism, this study developed a deep-fertilization mechanism with deformed gears and designed a deformed gear fertilization test bench. Single-factor and central composite design tests were performed with the planet carrier, spray hole size and pump pressure as the test factors, and the fertilizer amount as the test index. The results of the single-factor test showed a linear functional relationship between fertilizer amount and pump pressure, an exponential functional relationship between planet carrier velocity and fertilizer amount, and an exponential relationship between spray hole size and fertilizer amount. The rotating and perpendicular test data were analyzed and optimized using Design-Expert 8.0.5 software. The result of the optimization is: 10.5ml of fertilizer amount with pump pressure 0.36MPa, planet carrier velocity 82 r/min, and spray hole size 2 mm. The test result can meet the agronomic requirements.

Optimization of Small Peptide Feed from Milk Thistle Residue by Synergistic Fermentation of Multiple Strains and Proteases

In order to improve the utilization rate of the milk thistle residue, this study used the synergistic fermentation of multiple strains and proteases to increase the small peptide content of the fermented feed produced by the milk thistle residue. Taking the small peptide content of the milk thistle residue fermented feed as an indicator, the optimal fermentation process was obtained by single-factor optimization experiments and the response surface methodology. The optimal fermentation process was as follows: fermentation time of 7 days, inoculum size of 15%, inoculation ratio of aerobic strains: anaerobic strains = 1: 2, solid-state fermentation water content of 66%, fermentation temperature of 36℃, and amount of protease was 0.25% acid protease+0.25% bromelain. Under the above process, the small peptide content of the fermented feed from milk thistle residue was greatly improved to 57.86%. These results inferred that the added proteases were beneficial to the growth of fermentative microorganisms, the secretion of protease and the increase of the small peptide content.

Two Factor Authentication Berbasis SMS pada Layanan Single Sign-On Universitas Mataram

Keamanan merupakan bagian yang penting dalam hal transaksi elektronik. Sistem informasi di Universitas Mataram secara umum menggunakan metode username dan password untuk melakukan autentikasi (Single Factor Authentication - SFA). Metode SFA rentan dengan serangan brute force terhadap layanan Single Sign On (SSO). Untuk menangkal serangan brute force, penelitian ini mengusulkan implementasi Two Factor Authentication (TFA) berbasis SMS pada SSO. Penelitian ini menemukan pengujian yang dilakukan dengan melakukan analisa pada simulasi serangan brute force tidak dapat menembus akses dari akun pengguna. Pengujian lainnya dengan menggunakan metode User Experience Questionnaire (UEQ) menemukan skor pada aspek Pragmatis adalah 1,927 (Excellent), pada aspek Hedonis adalah 1,667 (Excellent), dan secara keseluruhan adalah 1,797 (Excellent).