Madschen Sia Mei Ol Siska

The design, construction, and commissioning of the ALICE Time-Projection Chamber (TPC) is described. It is the main device for pattern recognition, tracking, and identification of charged particles in the ALICE experiment at the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m3 and is operated in a 0.5 T solenoidal magnetic field parallel to its axis. In this paper we describe in detail the design considerations for this detector for operation in the extreme multiplicity environment of central Pb–Pb collisions at LHC energy. The implementation of the resulting requirements into hardware (field cage, read-out chambers, electronics), infrastructure (gas and cooling system, laser-calibration system), and software led to many technical innovations which are described along with a presentation of all the major components of the detector, as currently realized. We also report on the performance achieved after completion of the first round of stand-alone calibration runs and demonstrate results close to those specified in the TPC Technical Design Report.

ALICE (A Large Ion Collider Experiment) at the LHC contains a wide array of detector systems for measuring hadrons, leptons, and photons. ALICE is designed to carry out comprehensive measurements of high energy nucleus-nucleus collisions, in order to study QCD matter under extreme conditions and to study the phase transition between confined matter and the Quark-Gluon Plasma (QGP). Discussion of the full ALICE physics program can be found in [1, 2]. The interaction and energy loss of high energy partons in matter provides a sensitive tomographic probe of the medium generated in high energy nuclear collisions (“jet quenching”) [3–6]. Jet quenching measurements have played a key role at the Relativistic Heavy Ion Collider (RHIC) [7–10] and will be central to the study of nuclear collisions at the LHC. This Technical Design Report describes a large acceptance Electromagnetic Calorimeter (EMCal) that will be installed in the ALICE central detector. The EMCal enhances ALICE's capabilities for jet quenching measurements. The addition of the EMCal enables triggering on high energy jets, reduces significantly the measurement bias for jet quenching studies, improves jet energy resolution, and augments existing ALICE capabilities to measure high momentum photons and electrons. Combined with ALICE's excellent capabilities to track and identify particles from very low pt to high pt the EMCal enables an extensive study of jet quenching at the LHC.

The Banjar tribe in South Kalimantan has a traditional Bubungan Tinggi house, which is intended for nobles. This house is made of wood, in the form of a stilt with one roof angled upwards. This paper examines the solar geometry factor on the high ridge house, which is found on the pointed roof having a small geometric factor, so that the solar energy absorbed on the taper roof is small. This proves the local wisdom of the community in getting thermal comfort in their homes.

Rumah adat Banjar dengan atap tinggi (Bubungan Tinggi) merupakan rumah adat yang diperuntukkan bagi kalangan bangsawan kerajaan. Di zaman modern, jenis bangunan ini digunakan sebagai desain arsitektur bangunan pemerintahan. Rumah adat sebagai warisan budaya mengandung kearifan lokal, dimana rumah didesain agar mampu beradaptasi dengan lingkungan, sehingga orang yang tinggal di dalamnya dapat merasa nyaman. Pada penelitian ini, dikaji karakteristik termal dari rumah Banjar bubungan tinggi, dengan menggunakan metode simulasi CFD. Hasil yang didapatkan bahwa desain atap bubungan tinggi sangat menguntungkan dalam hal serapan energi matahari, dimana atap tersebut mempunyai koefisien geometri (Rb) kecil, sehingga tidak banyak terpapar secara frontal terhadap sinar matahari. Bentuk atap tinggi juga akan menimbulkan banyak bayangan yang menaungi dengan maksimal. Pada hasil simulasi CFD, didapatkan bahwa atap bubungan tinggi menjadi tempat terkumpulnya udara panas, dikarenakan perbedaan tekanan dan gaya apung udara, sehingga udara panas akan naik dan terkumpul di atap yang lebih tinggi. Untuk menghindari terkumpulnya udara panas yang lebih banyak, maka rekayasa mekanik yang dapat dilakukan adalah dengan memasang blower yang dapat menghembus udara panas ke lingkungan, sehingga dapat membantu sirkulasi udara ruangan.