Person:
DİRİM, MEHMET SABRİ

Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

DİRİM

First Name

MEHMET SABRİ

Name

Filters

2019 - 201912020 - 20231
Reset filters

Settings

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Publication
    The determination of soil boron fractions, their relationships to soil properties and the availability to olive ( olea europea l.) trees
    (Taylor & Francis Inc, 2019-04-14) Gürel, Serhat; GÜREL, SERHAT; Başar, Haluk; BAŞAR, HALUK; Keskin, Ece; Dirim, Mehmet Sabri; DİRİM, MEHMET SABRİ; Ziraat Fakültesi; 0000-0003-0019-3482; 0000-0001-9901-6499; AAH-3316-2021; AAH-2469-2021
    This study was conducted to investigate the various boron fractions in olive tree grown soils. The correlations between boron fractions in leaves, fruits and soil properties were examined. For this purpose cv "Gemlik" olive (Olea europaea L.) orchards were visited. Soil samples from 0-30 cm and 30-60 cm deep, the leaf and fruit samples were collected. The greatest proportion of total soil boron is present in residual form (85-88%). It is followed by organically bound B (2.84-4.50%), specifically adsorbed on soil colloid surfaces (0.93-1.31%), oxides (manganese oxyhydroxides, amorphous Fe and Al oxides, crystalline Fe and Al oxides) bound B (7.27-8.31%). The smallest one readily soluble (extracting plant available) boron values were composed of only 0.40-0.50% of total boron ranging. To determine readily soluble boron five different extraction solutions were in the order Hot water > 0.01 M CaCl2 > 1 M NH4OAc > 0.1 M KCl > 0.005 M DTPA. Fruit boron concentration and soil boron fractions showed close correlations than leaf boron concentration.
  • No Thumbnail Available
    Publication
    Experimental analysis of the volumetric and thermal efficiency performance of a novel direct piezo-acting cvvt mechanism
    (Taylor & Francis Inc, 2023-06-22) Sürmen, Ali; SÜRMEN, ALİ; Karamangil, M., I; KARAMANGİL, MEHMET İHSAN; Avcı, A.; AVCI, ATAKAN; Dirim, B.; DİRİM, MEHMET SABRİ; Işıklı, F.; IŞIKLI, FIRAT; Tekin, M.; TEKİN, MERVE; Türköz, N.; Mühendislik Fakültesi; Makine Mühendisliği Bölümü; 0000-0003-1662-5649; 0000-0003-2831-3175; 0000-0002-9009-8069; AAH-8619-2019; AAG-8571-2021; JCN-8081-2023; HNS-2001-2023
    In this study, a specifically designed direct-acting continuously variable valve timing mechanism was used to determine speed optimised valve timings for best volumetric efficiency of an engine. This mechanism basically consists of a piezo stack and a hydraulic magnifier integrated into it. To avoid effects of excessive vibrations on the piezo-stack, the engine was operated in a non-combustion mode. An electric motor was used to power the engine. Some system limitations of the hydraulic magnifier and the piezo-stack were the main challenges to a non-stop operation. A valve lift of approximately 4 mm, obtained with maximum applicable voltage of 600V to the piezo-stack, was referred to for comparison instead of the 7.6 mm original value. Tests were conducted for 30 inlet valve timing combinations at four different engine speeds from 1500 to 3000 rpm with 500 rpm increments. Timing pairs for the best VE were determined. They yielded 11.5% to 19.4% better volumetric efficiencies at 4mm lift than those obtained with the original valve timing of the cold engine. We also predicted 5-11.5% overall efficiency improvement, depending on engine type and operating conditions. Despite some practical challenges, better VE values have been obtained for a specific engine at varied speeds.