Aplikasi Hukum Termodinamika Dalam Kehidupan Sehari- hari (MPG CAPS)

 Di zaman modern ini, kebutuhan semakin meningkat dan harga semakin melunjak tinggi. Terutama BBM (Bahan Bakar Minyak) yang sekarang ini akan mengalami kenaikan. Hal ini di sebabkan karena harga minyak dunia naik oleh karena itu berdampak pada kenaikan BBM terutama di Indonesia. Salah satu dampak dari kenaikan BBM ini adalah semakin sakitnya hidup rakyat kecil atau rakyat miskin. Menurut saya, adapun tindakan yang dapat kita lakukan dalam mengurangi penggunaan energi di tengah mahalnya harga BBM salah satunya dengan menggunakan produk full additive yaitu MPG Caps yang merupakan produk untuk menghemat pengeluaran para pengguna kendaraan bermotor.

     MPG Caps (Mileages Per Gallon Capsule) adalah produk yang berbentuk kapsul di gunakan untuk merawat mesin yang di produksi oleh Fuel Freedom Internasional di Amerika Serikat yang 100% terbuat dari bahan organik aktif yang tidak mengandung filter. MPG Caps dapat digunakan untuk semua jenis bahan bakar seperti bensin, solar dan biodiesel. MPG Caps berfungsi untuk meningkatkan mileage per gallon kendaraan, meningkatkan umur klep mesin dan busi mesin, mencegah pembentukan limbah sisa-sisa pembakaran yang tidak diinginkan dalam mesin, mengurangi peningkatan karbondioksida setelah mesin bekerja.

     Hubungan antara termodinamika dengan suatu mesin adalah relasi termodinamik yang menunjukkan bahwa efisiensi termal dalam suatu sistem mesin motor adalah presentasi perbandingan kuantitas tenaga mekanik keluaran dan kuantitas tenaga panas masukan yang bila di jabarkan secara matematika fisika berdasarkan hukum termodinamika adalah :

Di mana :

Q1 : kuantitas tenaga panas masukan

Q2 : kuantitas tenaga panas keluaran

W : energi mekanik keluaran / tenaga mesin

 n  : efisiensi termal

     Kuantitas BBM pada kendaraan bermotor yang berhasil di ubah mesin menjadi gerakan mesin sekitar 70%. Berdasarkan pada rumus di atas efisiensi dapat di perbesar dengan dua cara yaitu :

1. memperkecil kuantitas input pada kuantitas output efektif tetap atau sebaliknya.

2. memperbesar kuantitas output efektif pada kuantitas output efektif pada kuantitas input tetap.

Adapun cara untuk meningkatkan efisiensi termal mesin antara lain adalah sebagai berikut :

• Meningkatkan rasio kompersi mesin menjadi lebih besar daripada 9.

• Meningkatkan suhu penyalaan dan pembakaran via peningkatan tegang elektroda busi, dengan mengganti koil penyalaan atau menambahkan SPB antara koil dan busi dan mengganti busi dengan yang lebih tahan panas.

• Meniadakan endapan kerak arang dalam ruang silinder mesin dengan cara meningkatkan pembakaran BBM.

      MPG Caps bekerja sebagai suatu katalis yang mempercepat mesin dalam melakukan pembakaran sehingga meningkatkan efisiensi mesin. Di dalam bahan bakar terdapat cairan yang dapat membawa dan menghantarkan kapsul ke ruang pembakaran mesin. Hal ini mengakibatkan mempercepat dan menyempurnakan reaksi pembakaran BBM. Bahan bakar akan semakin efisien sehingga mesin lebih irit. Penggunaan MPG Caps ini dapat mengirit penggunaan bahan bakar sekitar 12%. Manfaat lainnya adalah dapat mengurangi emisi gas rumah kaca, yang mengurangi efek global warning. Jadi, pada saat keadaan Indonesia mengalami kenaikan BBM ini, MPG Caps sangat membantu dalam proses pengiritan BBM hingga 12%.

SOURCE : http://murninana.blogspot.com/2013/05/aplikasi-termodinamika-dalam-kehidupan.html

Theory of heat capacity

Factors that affect specific heat capacity

For any given substance, the heat capacity of a body is directly proportional to the amount of substance it contains (measured in terms of mass or moles or volume). Doubling the amount of substance in a body doubles its heat capacity, etc.

However, when this effect has been corrected for, by dividing the heat capacity by the quantity of substance in a body, the resulting specific heat capacity is a function of the structure of the substance itself. In particular, it depends on the number of degrees of freedom that are available to the particles in the substance, each of which type of freedom allows substance particles to store energy. The translational kinetic energy of substance particles is only one of the many possible degrees of freedom which manifests as temperature change, and thus the larger the number of degrees of freedom available to the particles of a substance other than translational kinetic energy, the larger will be the specific heat capacity for the substance. For example, rotational kinetic energy of gas molecules stores heat energy in a way that increases heat capacity, since this energy does not contribute to temperature.

In addition, quantum effects require that whenever energy be stored in any mechanism associated with a bound system which confers a degree of freedom, it must be stored in certain minimal-sized deposits (quanta) of energy, or else not stored at all. Such effects limit the full ability of some degrees of freedom to store energy when their lowest energy storage quantum amount is not easily supplied at the average energy of particles at a given temperature. In general, for this reason, specific heat capacities tend to fall at lower temperatures where the average thermal energy available to each particle degree of freedom is smaller, and thermal energy storage begins to be limited by these quantum effects. Due to this process, as temperature falls toward absolute zero, so also does heat capacity

Degrees of freedom

Molecules are quite different from the monatomic gases like helium and argon. With monatomic gases, thermal energy comprises only translational motions. Translational motions are ordinary, whole-body movements in 3D space whereby particles move about and exchange energy in collisions—like rubber balls in a vigorously shaken container (see animation here ^[16]). These simple movements in the three dimensions of space mean individual atoms have three translational degrees of freedom. A degree of freedom is any form of energy in which heat transferred into an object can be stored. This can be in translational kinetic energy, rotational kinetic energy, or other forms such as potential energy in vibrational modes. Only three translational degrees of freedom (corresponding to the three independent directions in space) are available for any individual atom, whether it is free, as a monatomic molecule, or bound into a polyatomic molecule.

As to rotation about an atom's axis (again, whether the atom is bound or free), its energy of rotation is proportional to the moment of inertia for the atom, which is extremely small compared to moments of inertia of collections of atoms. This is because almost all of the mass of a single atom is concentrated in its nucleus, which has a radius too small to give a significant moment of inertia. In contrast, the spacing of quantum energy levels for a rotating object is inversely proportional to its moment of inertia, and so this spacing becomes very large for objects with very small moments of inertia. For these reasons, the contribution from rotation of atoms on their axes is essentially zero in monatomic gases, because the energy spacing of the associated quantum levels is too large for significant thermal energy to be stored in rotation of systems with such small moments of inertia. For similar reasons, axial rotation around bonds joining atoms in diatomic gases (or along the linear axis in a linear molecule of any length) can also be neglected as a possible "degree of freedom" as well, since such rotation is similar to rotation of monatomic atoms, and so occurs about an axis with a moment of inertia too small to be able to store significant heat energy.

In polyatomic molecules, other rotational modes may become active, due to the much higher moments of inertia about certain axes which do not coincide with the linear axis of a linear molecule. These modes take the place of some translational degrees of freedom for individual atoms, since the atoms are moving in 3-D space, as the molecule rotates. The narrowing of quantum mechanically determined energy spacing between rotational states results from situations where atoms are rotating around an axis that does not connect them, and thus form an assembly that has a large moment of inertia. This small difference between energy states allows the kinetic energy of this type of rotational motion to store heat energy at ambient temperatures. Furthermore internal vibrational degrees of freedom also may become active (these are also a type of translation, as seen from the view of each atom). In summary, molecules are complex objects with a population of atoms that may move about within the molecule in a number of different ways (see animation at right), and each of these ways of moving is capable of storing energy if the temperature is sufficient.

The heat capacity of molecular substances (on a "per-atom" or atom-molar, basis) does not exceed the heat capacity of monatomic gases, unless vibrational modes are brought into play. The reason for this is that vibrational modes allow energy to be stored as potential energy in intra-atomic bonds in a molecule, which are not available to atoms in monatomic gases. Up to about twice as much energy (on a per-atom basis) per unit of temperature increase can be stored in a solid as in a monatomic gas, by this mechanism of storing energy in the potentials of interatomic bonds. This gives many solids about twice the atom-molar heat capacity at room temperature of monatomic gases.

However, quantum effects heavily affect the actual ratio at lower temperatures (i.e., much lower than the melting temperature of the solid), especially in solids with light and tightly bound atoms (e.g., beryllium metal or diamond). Polyatomic gases store intermediate amounts of energy, giving them a "per-atom" heat capacity that is between that of monatomic gases (³⁄₂ R per mole of atoms, where R is the ideal gas constant), and the maximum of fully excited warmer solids (3 R per mole of atoms). For gases, heat capacity never falls below the minimum of ³⁄₂ R per mole (of molecules), since the kinetic energy of gas molecules is always available to store at least this much thermal energy. However, at cryogenic temperatures in solids, heat capacity falls toward zero, as temperature approaches absolute zero.

Table of specific heat capacities

 

Note that the especially high molar values, as for paraffin, gasoline, water and ammonia, result from calculating specific heats in terms of moles of molecules. If specific heat is expressed per mole of atoms for these substances, none of the constant-volume values exceed, to any large extent, the theoretical Dulong-Petit limit of 25 J·mol⁻¹·K⁻¹ = 3 R per mole of atoms (see the last column of this table). Paraffin, for example, has very large molecules and thus a high heat capacity per mole, but as a substance it does not have remarkable heat capacity in terms of volume, mass, or atom-mol (which is just 1.41 R per mole of atoms, or less than half of most solids, in terms of heat capacity per atom).

In the last column, major departures of solids at standard temperatures from the Dulong-Petit law value of 3 R, are usually due to low atomic weight plus high bond strength (as in diamond) causing some vibration modes to have too much energy to be available to store thermal energy at the measured temperature. For gases, departure from 3 R per mole of atoms in this table is generally due to two factors: (1) failure of the higher quantum-energy-spaced vibration modes in gas molecules to be excited at room temperature, and (2) loss of potential energy degree of freedom for small gas molecules, simply because most of their atoms are not bonded maximally in space to other atoms, as happens in many solids

Notable minima and maxima are shown in maroon
Table of specific heat capacities at 25 °C (298 K) unless otherwise noted.[citation needed] Substance	Phase	Isobaric mass heat capacity cP J·g−1·K−1	Isobaric molar heat capacity CP,m J·mol−1·K−1	Isochore molar heat capacity CV,m J·mol−1·K−1	Isobaric volumetric heat capacity CP,v J·cm−3·K−1	Isochore atom-molar heat capacity in units of R CV,am atom-mol−1
Air (Sea level, dry, 0 °C (273.15 K))	gas	1.0035	29.07	20.7643	0.001297	~ 1.25 R
Air (typical room conditionsA)	gas	1.012	29.19	20.85	0.00121	~ 1.25 R
Aluminium	solid	0.897	24.2		2.422	2.91 R
Ammonia	liquid	4.700	80.08		3.263	3.21 R
Animal tissue (incl. human)[27]	mixed	3.5			3.7*
Antimony	solid	0.207	25.2		1.386	3.03 R
Argon	gas	0.5203	20.7862	12.4717		1.50 R
Arsenic	solid	0.328	24.6		1.878	2.96 R
Beryllium	solid	1.82	16.4		3.367	1.97 R
Bismuth[28]	solid	0.123	25.7		1.20	3.09 R
Cadmium	solid	0.231	26.02			3.13 R
Carbon dioxide CO2[23]	gas	0.839*	36.94	28.46		1.14 R
Chromium	solid	0.449	23.35			2.81 R
Copper	solid	0.385	24.47		3.45	2.94 R
Diamond	solid	0.5091	6.115		1.782	0.74 R
Ethanol	liquid	2.44	112		1.925	1.50 R
Gasoline (octane)	liquid	2.22	228		1.64	1.05 R
Glass[28]	solid	0.84
Gold	solid	0.129	25.42		2.492	3.05 R
Granite[28]	solid	0.790			2.17
Graphite	solid	0.710	8.53		1.534	1.03 R
Helium	gas	5.1932	20.7862	12.4717		1.50 R
Hydrogen	gas	14.30	28.82			1.23 R
Hydrogen sulfide H2S[23]	gas	1.015*	34.60			1.05 R
Iron	solid	0.450	25.09[29]		3.537	3.02 R
Lead	solid	0.129	26.4		1.44	3.18 R
Lithium	solid	3.58	24.8		1.912	2.98 R
Lithium at 181 °C[30]	liquid	4.379	30.33		2.242	3.65 R
Magnesium	solid	1.02	24.9		1.773	2.99 R
Mercury	liquid	0.1395	27.98		1.888	3.36 R
Methane at 2 °C	gas	2.191	35.69			0.66 R? 4.23R
Methanol[31]	liquid	2.14	68.62			1.38 R
Molten salt (142-540 °C)[32]	liquid	1.56			2.62
Nitrogen	gas	1.040	29.12	20.8		1.25 R
Neon	gas	1.0301	20.7862	12.4717		1.50 R
Oxygen	gas	0.918	29.38	21.0		1.26 R
Paraffin wax C25H52	solid	2.5 (ave)	900		2.325	1.41 R
Polyethylene (rotomolding grade)[33][34]	solid	2.3027
Silica (fused)	solid	0.703	42.2		1.547	1.69 R
Silver[28]	solid	0.233	24.9		2.44	2.99 R
Sodium	solid	1.230	28.23			3.39 R
Steel	solid	0.466
Tin	solid	0.227	27.112			3.26 R
Titanium	solid	0.523	26.060			3.13 R
Tungsten[28]	solid	0.134	24.8		2.58	2.98 R
Uranium	solid	0.116	27.7		2.216	3.33 R
Water at 100 °C (steam)	gas	2.080	37.47	28.03		1.12 R
Water at 25 °C	liquid	4.1813	75.327	74.53	4.1796	3.02 R
Water at 100 °C	liquid	4.1813	75.327	74.53	4.2160	3.02 R
Water at −10 °C (ice)[28]	solid	2.11	38.09		1.938	1.53 R
Zinc[28]	solid	0.387	25.2		2.76	3.03 R
Substance	Phase	Isobaric mass heat capacity cP J·g−1·K−1	Isobaric molar heat capacity CP,m J·mol−1·K−1	Isochore molar heat capacity CV,m J·mol−1·K−1	Isobaric volumetric heat capacity CP,v J·cm−3·K−1	Isochore atom-molar heat capacity in units of R CV,am atom-mol−1

   source :

http://en.wikipedia.org/wiki/Heat_capacity